Essentials of Human Anatomy & Physiology, 13th Edition Marieb and Keller Solution Manual

Type:

Solution Manual

Resource:

Essentials of Human Anatomy & Physiology

Edition:

13th Edition

Author(s):

Elaine N. Marieb Suzanne M. Keller

CHAPTER

1

The Human Body An Orientation

Chapter Summary Chapter 1 emphasizes the relevance of anatomy and physiology in explaining the phenomena that occur in the body every day. It introduces and establishes the framework upon which all the other chapters are built. This chapter provides the necessary terminology so that instructor and students are all “speaking the same language.” It begins by defining the key terms anatomy and physiology, and then continues to describe the ways in which these key terms are interrelated. It is important that students understand the concept of complementarity of structure and function in the body. Structure determines function; the various body structures in their form are most efficient for the particular function that the structure performs. This concept will help students to master the more difficult material in future chapters. It is also important to emphasize to students that this course is similar to a language class in that new, unfamiliar terminology will be introduced; this course requires students to begin to learn the language of medicine. This language is a universal one shared by medical professionals across various specializations, and it is one that the students will repeatedly “speak” in their future allied health careers.

Levels of hierarchical structural/anatomical organization in the body are presented next, beginning with the atomic building block level and progressing through to the highest level of organization, the human body. A brief overview of each organ system follows, with a focus on the ways in which all the organ systems are interconnected into a working whole. This concept is presented through the discussion of the eight necessary life functions, since it is important for students to understand that each of the organ systems has several functions and that any given function is actually carried out by several organ systems working together. For example, excretion is not only overseen by the urinary system; it is also carried out and/or monitored by the endocrine, integumentary, respiratory, and cardiovascular systems. The five survival needs of the body to accomplish the necessary life functions are then discussed. The next section then provides the basic terminology that will be used and expanded upon throughout the text. Instructors should emphasize anatomical position and the midline of the body as an axis point. To that end, directional terms referencing trunk attachment points, such as proximal and distal, or midline reference points, such as medial and lateral, are introduced.

Regional terms are then discussed to address anterior and posterior body landmarks. Terminology for body sections and planes, as well as classification of body cavities and their respective components, round out the introduction of medical terminology.

The final section of this chapter ends with a discussion of homeostasis, the ability of the organ systems to cohesively function to respond to the ever-changing environment, as well as consequent disease states that occur when homeostasis cannot be achieved or resolved. Students appreciate the image of the dynamic body continually striving to maintain balance and equilibrium.

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Suggested Lecture Outline I. 1.1 An Overview of Anatomy and Physiology (pp. 1–2) A. 1.1a Anatomy (pp. 1–2) B. 1.1b Physiology (p. 2)

TEACHING TIP

C. 1.1c Relationship between Anatomy and Physiology (p. 2)

II. 1.2 Levels of Structural Organization (pp. 2–7) A. 1.2a From Atoms to Organisms (pp. 2–3) B. 1.2b Organ System Overview (pp. 3–7) 1. Integumentary System 2. Skeletal System 3. Muscular System 4. Nervous System 5. Endocrine System 6. Cardiovascular System 7. Lymphatic System 8. Respiratory System 9. Digestive System 10. Urinary System 11. Reproductive System

III. 1.3 Maintaining Life (pp. 7–10) A. 1.3a Necessary Life Functions (pp. 7–9) 1. Maintaining Boundaries 2. Movement 3. Responsiveness 4. Digestion 5. Metabolism 6. Excretion 7. Reproduction 8. Growth B. 1.3b Survival Needs (pp. 9–10)

IV. 1.4 The Language of Anatomy (pp. 10–18) A. 1.4a Anatomical Position (p. 11) B. 1.4b Directional Terms (pp. 11–13) C. 1.4c Regional Terms (pp. 13–14) 1. Anterior Body Landmarks 2. Posterior Body Landmarks D. 1.4d Body Planes and Sections (pp. 14–16) E. 1.4e Body Cavities (pp. 16–18) 1. Dorsal Body Cavity ..

Build a language of A&P. Use commonly used words to help students decipher the meanings of anatomical terminology. For example, for hypogastric, break the word down to hypo (use a term like hypodermic needle to lead the students to understand hypo means “below” as in below the skin surface) and gastric (similarly, use the term gastric bypass surgery, from which the students will derive the word stomach). Have students make flash cards of commonly encountered A&P word roots, prefixes, and suffixes, then have students combine the word parts in different ways to create new terms. In discussing medical conditions, point out the use of these same word parts to form medical terms.

Students are usually excited to see how quickly their vocabulary expands with their increasing knowledge of word parts.

MEDIA TIP NOVA: Inside the Human Body (PBS; 240 min., 2004). Using microphotography, NOVA presents the microworld of the human body.

Inside the Human Body (National Geographic; 50 min., 2007). The development of the human body from birth to old age is viewed through microscopic videography.

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2. Ventral Body Cavity 3. Other Body Cavities

V. 1.5 Homeostasis (pp. 18-20) A. 1.5a Components of Homeostatic Control Systems (pp. 18–19) B. 1.5b Feedback Mechanisms (pp.19–20) Note: For a list of Key Terms for this chapter go to Mastering A&P > Study Area > Additional Study Tools > Key Terms > Chapter 1.

Learning Objectives 1-1

Define anatomy and physiology.

1-2

Explain how anatomy and physiology are related.

1-3

Name the six levels of structural organization that make up the human body, and explain how they are related.

1-4

Name the organ systems of the body, and briefly state the major functions of each system.

1-5

Identify and classify by organ system all organs discussed.

1-6

List eight functions that humans must perform to maintain life.

1-7

List the five survival needs of the human body.

1-8

Verbally describe or demonstrate the anatomical position.

1-9

Use proper anatomical terminology to describe body directions, surfaces, and body planes.

1-10 Locate the major body cavities, and list the chief organs in each cavity.

1-11 Define homeostasis, and explain its importance.

1-12 Define negative feedback, and describe its role in maintaining homeostasis and normal body function.

Resources for Teaching Online Discussion Board Topic: Homeostatic Imbalance—Aging In the textbook on page 20, the Homeostatic Imbalance section explains that most disease results from the disturbance of homeostasis. Engage your students by using the following discussion question in lecture or by posting it to the discussion board on your course management system.

Discussion Questions 1. The textbook cites aging as a cause of homeostatic imbalance, where body processes become inefficient, thus leading to changes in the body, including higher incidences of illness. One aging-related disease is osteoarthritis. Why is osteoarthritis common in elderly populations? What is the age of onset?

2. How can osteoarthritis be caused in non-elderly populations?

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3. Which medical imaging techniques are used to diagnose osteoarthritis?

4. What are the current treatment options for osteoarthritis?

Potential Student Responses: 1. Osteoarthritis is also known as the “wear and tear” arthritis. Over time, the articular cartilage will erode, tendons and ligaments can stretch, and bones can generate friction against each other. Most people over 60 years of age will have some degree of osteoarthritis.

2. Osteoarthritis can also be a secondary result of a trauma or repetitive occupational/sportsrelated joint stress from overuse, which can occur even as early as in the 20s. Since osteoarthritis often affects weight-bearing joints, obesity can prematurely cause osteoarthritis as well.

3. The conventional diagnostic imaging technique is radiography, which will allow visualization of localized narrowing of the joint spaces, sclerosis, and/or bone spurs in the joint, which are all hallmark symptoms of osteoarthritis. In addition, other diagnostic techniques can be used. MRIs can detect reactive bone edema, soft tissue swelling, or cartilage and bone fragments in the joint; CTs can determine the degree of bone spur formation; and ultrasound can detect synovial cysts that may be found in association with osteoarthritis.

4. Although there are no procedures to cure osteoarthritis, there are treatments to alleviate the pain associated with the disease. NSAIDs, acetaminophen, cortisone injections, physical therapy, synovial fluid injections, osteotomies, and joint replacement surgeries are some treatment options, depending on the degree of damage caused by osteoarthritis.

Investigate Online Take learning a step further by searching for relevant research articles on the web. Visit science websites, such as those listed below, and begin by searching for key terms such as accident and trauma, abdominal cavity, abdominopelvic organs, and solid organ injury and see what you’re learning in the course applies to science and medicine today. www.sciencedaily.com www.scientificamerican.com www.the-scientist.com www.ncbi.nlm.nih.gov/pubmed www.aaos.org

Study Tips Direct students to the Study Tips feature located in the front of the book.

Mastering A&P Numerous items from Mastering A&P can be demonstrated in class, assigned as homework, or encouraged as study materials. These include practice tests and quizzes, animations and videos, ..

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Interactive Physiology (IP), Dynamic Study Modules, Audio Journeys, Practice Anatomy Lab (PAL), PhysioEx, flashcards, glossary, key terms, and more.

Animations and Videos The following videos are relevant to this chapter:

Bone and Dissection Videos > Fetal Pig Dissection > Organs of the Digestive System

Practice Anatomy Lab (PAL)3.1: Including Mobile Flashcards The following section of PAL3.1 are relevant to this chapter:

Fetal Pig > Overview of Internal Organs

Lecture Hints 1. To illustrate the basic concept of anatomy = structure and physiology = function, micrographs or models of organs or various cells of the body can be shown. An effective organ system to use as an illustration for structure dictating function is the respiratory system, where macroscopic structures such as the nasal passages and trachea are specialized for conduction of air, and structural characteristics to aid respiratory function can continue to be described down to the level of the alveoli, which are composed of simple squamous cells; the one-layer thickness allows simple diffusion of O2 and CO2. Other microscopiclevel examples are cells, such as macrophages that look and function similar to amoebas with their phagocytosis, as well as neurons that have extensive processes to facilitate cellular communication.

Key point: Physiology, or function, is dependent on anatomy. Use the analogy that the body is really a well-designed machine for optimal function of life processes. A slight change in anatomy can have a significant effect on physiology. For example, in sickle cell anemia, the normal biconcave structure of the red blood cell is altered to a crescent/sickle shape, which causes the reduction of the oxygen-carrying capacity of the red blood cells.

2. Discuss the differences between microscopic and macroscopic (gross) anatomy, where microscopic is at the level of cells and tissues, and macroscopic is at the organ level.

Reference the relevance to such specialties as pathology and microbiology.

Key point: Point out to students that dissection is aimed at helping us to understand the functions of each of the various levels of organization, but that the body works as a whole and is consequently more complex than the simple sum of its component parts.

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3. Starting with the concept of atoms joining to form molecules, have the students “build” a single organ system that then combines with other organs to form the living body.

Key point: Every level of the system relies on the smooth workings of the level preceding it, and a malfunction at any level may have life-threatening consequences to the levels built upon it.

4. Discuss each of the fundamental life functions (e.g., digestion, metabolism) and have students list all of the organ systems that contribute to this single function. Also point out secondary functions of organs; for example, the kidney is important for creating urine primarily, but it also has an endocrine role of producing and secreting erythropoietin to stimulate red blood cell production in the bone marrow.

Key point: It is important for students to understand that organ systems often have an obvious primary function, but that all the systems are closely interrelated and impact one another in numerous ways, including ways not yet identified.

5. Ask the students to describe the physiological effects of being outside for an extended period of time on a hot, summer day (sweating, feeling thirsty), and compare that to being outside on a cold, winter day (shivering). Outline the ways in which the body compensates for such variations in temperature and identify these mechanisms as homeostasis at work.

Key point: Point out to students that the body is still in a constant state of flux, balancing between a range of “normal” values that is rarely static.

6. A simple, clear method of demonstrating negative feedback is to discuss the thermostat in the classroom. Students can easily understand the negative feedback system of the HVAC system at work. Address the common misconception that the word “negative” must always mean something is bad. In this case, “negative” indicates that the response “reverses” the initial stimulus. This action is “good” because it maintains a variable near a setpoint.

Key point: Negative feedback loops are the chief regulators of homeostasis under normal healthy conditions. A rise in any given value (e.g., blood pH, heart rate, blood pressure) precipitates a reaction to lower it, until such time as it becomes too low, causing negative feedback to initiate responses to raise it again.

7. Positive feedback is more difficult to understand than negative feedback. An effective example is to set up a domino cascade, where one domino hits two dominoes that each in turn hit two more dominoes, and so on. Also give a real-world example, such as how wet nurses were able to nurse multiple children over a period of time.

Key point: Negative feedback loops are homeostatic because they keep a given variable at or near a setpoint. Positive feedback loops are not homeostatic because the response sends the variable even farther from its normal value. Like a nuclear reaction, positive feedback involves a series of chain reactions of ever-increasing magnitude. With positive feedback, something outside of the loop is required to stop the response. However, several important events in the body such as blood clotting, labor contractions, and breastfeeding are regulated by positive feedback loops.

8. Directional terms are best presented as opposites, with appropriate demonstrations for each. For example, anterior is easily distinguished from posterior, superior from inferi..

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or, and so on. The most difficult set to distinguish seems to be proximal and distal. Use a set of examples that demonstrate their relationship, such as elbow to wrist (the elbow is proximal in this instance) compared with elbow to shoulder (the elbow is distal in this instance), to help clarify the concept.

Key point: It is important for students to understand that proximal and distal terminology is used to describe the comparative distances of two limb structures from the point of attachment on the trunk of the body.

9. Point out to students how the terms ventral (anterior)/dorsal (posterior) and superior/inferior refer to different areas for bipeds and quadrupeds. In particular for ventral/dorsal, relate the dorsal fin of the shark. Show also the similarity of embryonic forms of various animals versus human to emphasize the derivation of this terminology. Also point out that directional terms are often combined to more accurately identify the relative position of a single structure. For instance, the nipple is superolateral to the belly button.

Key point: Just as more than one adjective can be used to describe a single noun, so can more than one directional term be used to describe a single structure.

10. Draw or show slides of various cells of the body, such as a smooth muscle cell, neuron, pseudostratified ciliated columnar cell of the trachea, and red blood cell without identifying the function or location of the cells. Have students hypothesize the function of the cell by analyzing its structure.

Key point: There is complementarity of structure and function; structure is driven by function. For example, neurons have processes that function to receive and convey information, and red blood cells are flattened to increase the ratio of surface area to volume and ease of diffusion of oxygen for maximal transport.

11. Provide students with opportunities to verbalize material and use appropriate terminology that you have covered in your lecture. The unfamiliar terms students are introduced to will have more meaning if they pronounce them out loud. Encourage students to study verbally while practicing vocabulary and explaining concepts. Encourage students to explain processes or mechanisms in their own words whenever possible. Remind students that the Study Area of Mastering A&P contains Additional Study Tools: Key Terms, Glossary, and Flashcards.

Key point: Science has its own language, as complex as English or any other language, and it takes time and concentrated effort to master. As with any new language, practice and repetition are the keys to development and long-term retention.

12. Have students use sticky notes with regional and directional terminology and put them on a classmate in class, or a friend or family member during their studies at home, and then use the book to double-check placement of terms. Have them take photographs or create a video and upload them into the learning management system or a class-assigned Google drive as an assignment.

Key point: Devise fun and creative exercises that will make the terminology more relevant and less intimidating to tackle.

13. With an articulated skeleton present, ask students to identify and locate body cavities.

Have students discuss the organs found within each cavity, and how protection to those 7

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organs is conferred (whether there is bony protection, skeletal muscle protection, fluid protection, etc.).

Key point: Explain that potential space is a space that exists but may be filled, such as the abdominal cavity, which is filled with organs; an uninflated balloon also has a potential space that can be filled with air or fluid. Students may need to be guided to certain cavities that are not as evident visually, such as to the middle ear cavity that houses the ossicles or to the paranasal sinuses.

Classroom Demonstrations and Student Activities Classroom Demonstrations 1. Dissect a small preserved animal (e.g., a fetal pig) to demonstrate the various organ systems of the body. Point out at least two organs from each organ system and discuss their function. If dissection is not an option, use images from Practice Anatomy Lab (PAL3.1) for internal organs in human cadaver, cat, or fetal pig as well as the fetal pig dissection videos located in Mastering A&P < Study Area < Bone and Dissection Videos. In addition, there are several films that can be substituted (see Media section) or other computer programs that offer virtual dissection experiences. Lastly, Carolina Biological Supply Company and other supply companies offer plastinated dissected specimens that can be passed around the classroom.

2. Use a human torso model to point out the dorsal and ventral body cavities and the organs in each cavity. Use this opportunity to also compare a quadruped animal with the biped human to illustrate the use of dorsal/ventral versus anterior/posterior at the level of the head.

3. Use a skeleton and human torso model to show directional terms in action. With a dissectible human torso model, first have students point out, for example, an organ that is superior to the liver. Then, once students are familiar with the gross anatomy, the various organs except for the one under discussion, such as the liver, can be laid out on a table and students can be asked to pick up an organ (or even all organs) superior to the one under discussion and replace them within the model. A skeletal model can be used to demonstrate the distinction between directional terms associated with point of attachment to the trunk (proximal and distal) versus on the trunk (superior and inferior).

4. Demonstrate various pulse points, some of which the students will already be familiar with. Relating these pulse points to regional terminology will help the students understand their usage.

5. Arrange for the class to attend an autopsy or take a tour of the anatomy lab at the local medical school (preferably after the material of Chapter 1 has been covered).

6. Thin, plastinated sections of the human body can be circulated for view in the classroom, allowing students to view the orientation and position of organs, as well as different body section views.

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7. Circulate photographic atlases of the human body in class or use cadaver images from Practice Anatomy Lab (PAL3.1). Compare these images with the idealized textbook illustrations.

8. Bring in a two-arm balance and demonstrate with weights how negative feedback works to maintain homeostasis or “balance.” Positive feedback can also be demonstrated with the balance. If a two-arm balance is not readily available, create a simple balance using a stick, string, and weighing boats.

9. Create emergency room scenarios using terminology from Chapter 1. Have the students determine the location of the illness or injury using regional and directional terms. Extend the exercise by either relating to homeostatic feedback mechanisms and/or challenging the students to brainstorm which body functions could be impacted by the illness or injury to those specific areas of the body.

Student Activities 1. Have students stand and assume the anatomical position. Ask the students to comment on how that position differs from the “usual” standing position and to explain why knowing this position is important to precisely identify anatomical terms and physiological processes.

2. Remove all the organs from the ventral and dorsal body cavities of a human torso model.

Ask for volunteers or assign students to return the organs to their proper anatomical location. As each organ is properly repositioned, have other students call out its name and organ system relationship.

3. Place a human torso model at center stage. Ask for a volunteer to come up and show how the torso model would be cut along the sagittal, frontal, and transverse planes. Have students come up with medical situations for which visualizations along each respective plane would elucidate diagnosis or function of specific organs/areas.

4. To initiate a class discussion on the relative degree of protection of organs in the dorsal versus the ventral body cavity, ask the class a question such as “Why do you think a dog instinctively curls over and protects its abdomen when that body region is approached (threatened by a blow, etc.) even playfully?” or “Two people have rapidly growing tumors. The tumor is in the dorsal cavity in one of these individuals and in the ventral cavity of the other. Which of these people will develop symptoms first, and why?”

5. Call out anatomical terms (buccal, femoral, etc.) and have the students (as a group) point out the named regions on their own bodies. Alternatively, organize students into small groups/teams for a quiz with a game show format with cards that have body landmarks they must demonstrate on their bodies or draw out. The key terms for each chapter are listed in the Mastering A&P Study Area > Additional Study Tools > Key Terms. .

6. Have students find a series of landmarks on their own bodies, providing a list of landmarks for the students to locate. Use real-life examples to help the students better understand the terminology. For example, the list could include items such as “the location where a necktie is worn,” “the location of a belly button piercing,” and so on. Have the students do this in small groups so they can discuss the terms with each other and begin to develop camaraderie among the group.

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7. Have students play a game of Simon Says with regional terms and directional terms. The leader can use instruction cards provided by the instructor; for more advanced play, the students can take turns coming up with their own commands using a combination of regional and directional terms.

8. Demonstrate the location of the radial, brachial, carotid, femoral, popliteal, and pedal pulses.

Have students try to locate several pulse points on themselves and their fellow students.

9. Have students get into groups of four or five. List five root words on the board and have the student groups come up with as many terms as they can think of that incorporate those roots. The terms can be common English, biological, or medical in nature, as long as a root word is found in each. Allow them 15 minutes to compile their lists, then compare the terms of the various groups. Point out their increased vocabulary based on the knowledge of a relatively small number of roots.

10. To help the students understand negative feedback, have them do a balancing exercise: bring in a bicycle or attach a slackline, for example, to show the compensations and adjustments done to maintain balance. Students should be able to articulate their compensating actions and able to understand that their actions are examples of negative feedback.

11. To encourage an understanding of organ system interrelationships, ask the students to comment on the functional relationships between muscles and bones, and between the respiratory and cardiovascular systems.

12. Use a simple battery-operated clock as an example to indicate the importance of relatively constant conditions on optimal functioning of any system. Ask the class to indicate what would happen if it was (a) immersed in water, (b) hit with a hammer, (c) heated until it was red-hot, and (d) had its battery removed. Then ask them what conditions would be best suited for the clock to operate properly, and ask them to provide a single term that describes those conditions (homeostasis).

13. Have students go up to the board and create a hierarchy chart, first listing the survival needs essential to sustain life, then listing which necessary life functions are needed to carry out each survival need, and finally listing what organ systems are involved to carry out the necessary life functions.

14. Have students create a flowchart for the major body cavities (dorsal subdivides into cranial and spinal; ventral subdivides into thoracic and abdominopelvic, which subdivides into abdominal and pelvic). Then have students assign organs to the correct cavities.

15. Student assignment for class discussion: Bring in an article from a popular magazine or newspaper describing an environmental problem(s), such as toxic waste disposal, pollution of the ocean, and so on, that threatens their homeostasis or even survival. Be prepared to describe the problem and how it represents a threat to the body.

16. Discuss current medical technology that is being used to treat various disorders such as pacemakers, prosthetics, or gene therapy. Have students speculate on what new technologies could emerge in the next decade, or even in the next century.

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Media See page 164 for a listing of media distributors.

1. Homeostasis (FHS: 20 min., 1995, DVD, 3-year streaming webcast). From The New Living Body series, live-action video, advanced imaging technology, and 3-D computer graphics show homeostatic mechanisms in the human body at work during a marathon.

2. Human Biology (FHS: 58 min., 1995, VHS, DVD). Live-action video sequences (21) provide an overview of human biology.

3. Human Body: The Ultimate Machine (CBS: 27 min., 2005, DVD). The body’s major systems are described through footage of surgical procedures, microphotography, and 3-D animation.

4. Introduction to the Body: Landscapes and Interiors (FHS: 28 min., 1984, VHS, DVD, 3year streaming webcast). Introduction to the award-winning The Living Body series, which shows the body’s adaptability to diverse climates and other homeostatic triggers.

5. Incredible Human Machine (National Geographic, 90 min., 2007, DVD). Tour of the human body describing organ systems through microphotography and CGI. 6. Human Anatomy and Physiology (Khan Academy website). Tutorial website on introduction of organ systems. www.khanacademy.org/science/health-and-medicine/humananatomy-and-physiology 7. Homeostasis (Khan Academy website). Video abouthomeostasis and thermoregulation. www.khanacademy.org/science/high-school-biology/hs-human-body-systems/hs-bodystructure-and-homeostasis/v/homeostasis

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CHAPTER

2

Basic Chemistry

Chapter Summary Chapter 2 provides an overview of basic chemistry relevant to human A&P. Although this is often a topic that students do not realize is essential in human A&P, and try to avoid, it is important to convey to them that the physical chemistry and molecular interactions covered in this chapter will serve as a foundation of knowledge for the mechanisms of physiological processes discussed throughout the rest of the course. For example, this chapter is important for gaining a better understanding of how membrane depolarization works in the nervous and muscular systems for communication (Chapters 6 and 7) and how dehydration synthesis and hydrolysis reactions participate and are integral in the biochemical metabolic pathways in the digestive system (Chapter 14).

This chapter begins with the fundamental concepts related to matter and energy, then proceeds to show the breakdown of matter into its components. A discussion of the periodic table reveals the way in which elements are arranged by their properties, which enables determination of element characteristics. The four most abundant elements in all living organisms (i.e., carbon, oxygen, hydrogen, and nitrogen) are emphasized.

Atomic structure is presented next, and the planetary and orbital models provide a framework upon which students begin to build their understanding of subatomic particle positioning. Atomic number, atomic mass (number), and atomic weight are discussed, followed by explanations of the characteristics of isotopes and their roles in health care assessment and medical treatment. The concepts presented about atomic structure lead naturally into a discussion of molecules and compounds. Chemical bonds and reactions are presented as a means by which molecules are continuously formed and destroyed. The differences among ionic, covalent, and hydrogen bonds are all discussed, as are synthesis and decomposition reactions.

The final section of this chapter provides an overview of biochemistry. The differences between organic and inorganic compounds are presented, along with applied examples of each. Water is noted to be the most abundant compound in the body, which helps students understand its role as the “universal solvent” of life. The discussion on the reactions of acids and bases then leads into the discussion of biochemical reactions in the body. The types of organic compounds (i.e., carbohydrates, lipids, proteins, and nucleic acids) further these concepts as students begin to see the importance of the proper utilization of these compounds in all body processes. The chapter concludes with an explanation of the importance of ATP as the energy fueling the metabolic processes of the body.

Suggested Lecture Outline

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I. 2.1 Concepts of Matter and Energy (pp. 23–25) A. 2.1a Matter (pp. 23–24) B. 2.1b Energy (pp. 24–25) 1. Forms of Energy a. Chemical Energy b. Electrical Energy c. Mechanical Energy d. Radiant Energy 2. Energy Form Conversions

TEACHING TIP Demonstrate the acidic or basic nature of household products in class to introduce pH. This can be done with the use of red cabbage juice (water that turns color after boiling a red cabbage for 30 minutes). Discuss how the red cabbage juice can function as an indicator.

Use lemon juice, coffee, milk, water, baking soda solution, and bleach to show the spectrum of acid-base pH color change. Vary the exercise by asking students their hypotheses as to which solutions are acidic or basic and why. Also initiate a discussion on how Alka-Seltzer or Pepto-Bismol works, and demonstrate by adding to lemon juice and then using the red cabbage juice indicator. This will drive home the concept of pH and acid– base to the students in an understandable and engaging manner.

II. 2.2 Composition of Matter (pp. 25–30) A. 2.2a Elements and Atoms (p. 25) B. 2.2b Atomic Structure (pp. 25–27) 1. The Basic Atomic Subparticles 2. Planetary and Orbital Models of an Atom C. 2.2c Identifying Elements (pp. 27–30) 1. Atomic Number 2. Atomic Mass Number 3. Atomic Weight and Isotopes

III. 2.3 Molecules and Compounds (pp. 30–31) IV. 2.4 Chemical Bonds and Chemical Reactions (pp.

31–37) A. 2.4a Bond Formation (pp. 31–35) 1. Role of Electrons 2. Types of Chemical Bonds a. Ionic Bonds b. Covalent Bonds c. Hydrogen Bonds B. 2.4b Patterns of Chemical Reactions (pp. 35–37) 1. Synthesis Reactions 2. Decomposition Reactions 3. Exchange Reactions 4. Factors Influencing the Rate of Chemical Reactions

MEDIA TIP Basic Chemistry for Biology Students (HRM: 21 min., 1993). Excellent video for clarifying basic chemistry concepts.

V. 2.5 Biochemistry: The Chemical Composition of Living Matter (pp. 37–55) A. 2.5a Inorganic Compounds (pp. 38–41) 1. Water

a. High heat capacity b. Polarity/solvent properties c. Chemical reactivity d. Cushioning 13

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2. Salts 3. Acids and Bases a. Characteristics of Acids b. Characteristics of Bases c. Acids, Bases, and Neutralization d. pH: Acid-Base Concentrations B. 2.5b Organic Compounds (pp. 41–55) 1. Carbohydrates a. Monosaccharides b. Disaccharides c. Polysaccharides 2. Lipids a. Triglycerides b. Phospholipids c. Steroids 3. Proteins a. Structural Levels of Proteins b. Fibrous and Globular Proteins c. Enzymes and Enzyme Activity 4. Nucleic Acids 5. Adenosine Triphosphate (ATP) Note: For a list of Key Terms for this chapter, please go to Mastering A&P > Study Area > Additional Study Tools > Key Terms > Chapter 2.

Learning Objectives 2-1

Differentiate matter from energy.

2-2

List four major energy forms, and provide one example of how each energy form is used in the body.

2-3

Define element, and list the four elements that form the bulk of body matter.

2-4

Explain how elements and atoms are related.

2-5

List the subatomic particles, and describe their relative masses, charges, and positions in the atom.

2-6

Define radioisotope, and describe briefly how radioisotopes are used in diagnosing and treating disease.

2-7

Define molecule, and explain how molecules are related to compounds.

2-8

Recognize that chemical reactions involve the interaction of electrons to make and break chemical bonds.

2-9

Differentiate between ionic, polar covalent, and nonpolar covalent bonds, and describe the importance of hydrogen bonds.

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2-11 Distinguish organic from inorganic compounds.

2-12 Explain the importance of water to body homeostasis, and provide several examples of the roles of water.

2-13 List several salts (or their ions) vitally important to body functioning.

2-14 Differentiate a salt, an acid, and a base.

2-15 Explain the concept of pH, and state the pH of blood.

2-16 Explain the role of dehydration synthesis and hydrolysis in formation and breakdown of organic molecules.

2-17 Compare and contrast carbohydrates and lipids in terms of their building blocks, structures, and functions in the body.

2-18 Differentiate fibrous proteins from globular proteins.

2-19 Define enzyme, and explain the role of enzymes.

2-20 Compare and contrast the structures and functions of DNA and RNA. 2-21 Explain the importance of ATP in the body.

Resources for Teaching Online Discussion Board Topic: Radioisotopes In the textbook on page 29, radioisotopes are defined as heavier, less stable variants of an element that tend to release energy in order to become more stable. Stability is accomplished by ejecting particles or electromagnetic energy from the nucleus. Engage your students by using the following discussion questions in lecture or by posting them to the discussion board on your course management system.

Discussion Questions 1. What are some diagnostic or therapeutic uses of radioisotopes?

2. What are the potential dangers of radioisotope use?

3. What is radiation hormesis? What do current scientific studies suggest?

Potential Student Responses: 1. Cancer treatment, hyperthyroidism, diagnostic imaging such as PET scans, nuclear powering of pacemakers, densitometry for osteoporosis determination, sterilization of medical supplies and equipment, and biochemical analysis of biological samples are a few possible answers.

2. Cancer, teratogenic effects, and developmental effects in children are some examples.

3. Radiation hormesis is the idea that small doses/levels of radiation can actually be beneficial. Scientists are still debating whether or not this is the case; scientific studies have shown both positive and negative results, so this may spark some debate with the students.

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Take learning a step further by searching for relevant research articles on the web. Visit science websites, such as those listed below, and begin by searching for key terms such as radioisotope therapy, radioisotope imaging, radioisotope treatment, radiation safety, and radiation hormesis, and see how what you’re learning in the course applies to science and medicine today. www.sciencedaily.com www.scientificamerican.com www.the-scientist.com www.ncbi.nlm.nih.gov/pubmed www.acr.org

Study Tips Direct students to the Study Tips feature located in the front of the book.

Mastering A&P Numerous items from Mastering A&P can be demonstrated in class, assigned as homework, or encouraged as study materials. These include practice tests and quizzes, animations and videos, Interactive Physiology (IP), Dynamic Study Modules, Audio Journeys, Practice Anatomy Lab (PAL), PhysioEx, flashcards, glossary, key terms, and more.

Interactive Physiology (IP) The following sections of Interactive Physiology are relevant to this chapter: Chemistry IP Animation: Chemistry

Animations and Videos The following videos are relevant to this chapter:

Get Ready for A&P Video Tutors > Atomic structure; Chemical Bonding Part 1: Introduction to Chemical Bonding; Chemical Bonding Part 2: Ionic Bonding; Chemical Bonding Part 3: Covalent Bonding; Chemical Bonding Part 4: Hydrogen Bonding

Additional Study Tools

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The following video is relevant to this chapter:

Focus on Careers > Pharmacy Technician

Lecture Hints 1. Introduce the topic of chemistry with an eye-catching experiment; for example, create a “volcano eruption” by combining baking soda and vinegar.

Go through the dissociation of ions in water: baking soda: NaHCO3 → Na+(aq) + HCO3−(aq) vinegar: CH3COOH  H+(aq) + CH3COO−(aq) Then the synthesis reaction of carbonic acid: H+ + HCO3− → H2CO3 Followed by the decomposition reaction where carbon dioxide is released: H2CO3 → H2O + CO2 CO2 is what causes the “volcano eruption.”

Key point: Show the fun side of chemistry. Many of the students are familiar with this experiment and may have done it themselves or with siblings or kids. This experiment will show how chemical reactions occur using common household products. Tie in decomposition and synthesis reactions to physiological processes in the body to relate chemical reactions to body function.

2. Remind students of the levels of structural organization, starting with the atom. Explain the relevance of chemistry to this hierarchy and reiterate that higher levels of complexity are dependent upon the smooth workings of preceding, less complex levels.

Key point: Because chemistry seems abstract to students, they often fail to understand its importance until that connection is made for them. Providing clear examples of some of the chemical reactions we use to sustain life (e.g., IV therapy, medication administration) helps them to put chemistry into its proper applied perspective.

3. Emphasize the fact that energy is neither created nor destroyed but can be converted from one form to another. Use food as an example, starting with electromagnetic radiation from the sun and ending with the chemical bonds of an ATP molecule in a human muscle cell.

Key point: It is important for students to understand that energy is never lost, it is just found in different forms, some of which we can capture and some of which, at this point, we cannot. It also illustrates the interrelationship between humans and their surrounding environment, which can extend class concepts of hierarchical organization by illustrating how humans can be a component of the biosphere.

4. Use the periodic table as a tool to discuss atoms and elements, and continue to use it while presenting the mechanics of bond formation. Work through a few examples (e.g., 17

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sodium reacting with chlorine), then have the students work through several combinations of elements contained within the same columns.

Key point: Once the students see how the elements react based on their valence electrons, they begin to form a clearer picture of the chemical properties of the elements.

5. Create partially filled-in areas on a periodic table and have the class work together to figure out, for example, the missing information on the number of protons and neutrons.

Key point: Students will become more comfortable with the terms atomic number, atomic mass, atomic weight, and isotopes.

6. Use as many visual aids as you can to demonstrate bonding patterns between atoms. Balland-stick models or Zometool models are optimal.

Key point: The more experience students have with forming molecules and compounds in model form, the better their understanding of the various bond formations.

7. Explain the tendency of elements with fewer than four electrons in their valence shell “to want” to lose those electrons, while elements with more than four electrons in their valence shell “want” to gain electrons, all in the name of achieving “stability.” Further explain that it is when there are four electrons in the valence shell that the element doesn’t “want” to gain or lose electrons but is “willing” to share electrons. Note that only a few elements (the noble gases) come equipped with a stable valence shell and that prolonged excess of highly reactive unstable molecules within the body upsets homeostasis and may cause chronic diseases.

Key point: The entire field of organic chemistry is dependent upon these principles.

Carbon has the capacity to form not only single bonds but also double and triple bonds, making it a very versatile element. Without the property of carbon to share electrons, life on Earth would be entirely different or not existent at all. It is important to emphasize that humans are carbon-based organisms, as are all living things on our planet.

8. Ionic bonds form when electrons are transferred from one atom to another. In covalent bonds, electrons are shared among the atoms of the molecule.

Key point: It is important for students to understand that ionic bonds are formed between atoms that are very different in their electronegativity, while covalent bonds are formed from interacting atoms with similar electronegativities.

9. Make sure students understand that hydrogen bonds can be formed between molecules or can be formed within a molecule. Use water as an example of intermolecular hydrogen bonding, and use proteins for intramolecular bonding.

Key point: Hydrogen bonds, although weak, are important for holding the two strands of DNA together, providing the complex three-dimensional structure of large proteins, and for joining multiple water molecules together. For DNA, the hydrogen bonds allow for easy separation of the two strands during replication and transcription. Heating can denature proteins by breaking the hydrogen bonds.. Hydrogen bonds between neighboring water molecules allow for the phenomenon of surface tension of water, as discussed in #10.

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10. Discuss surface tension to explain the outcome of hydrogen bonds. Students have usually observed or experienced that when a glass is filled slowly with water, it can be filled past the rim of the glass. Discuss that the “skin of water” is due to hydrogen bonding.

Key point: Until students can visualize the effects of millions of hydrogen bonds holding water together, it is difficult for them to understand their importance.

11. Emphasize the fact that the larger the pH number, the smaller the concentration of hydrogen (H+) ions and thus the larger the relative concentration of hydroxyl (OH−) ions and the more alkaline the solution. The smaller the pH number is, the larger the concentration of hydrogen ions, and thus the more acidic the solution. This concept can be further demonstrated with pH meter measurements of lemon juice versus bleach. Each of these can be serially diluted tenfold, and the pH meter can illustrate the change in 1 pH unit.

Key point: Students frequently confuse this point. It is important to point out that each change of 1 pH unit represents a tenfold change in H+ ion concentration, and that there is an inverse relationship between H+ and OH− ions. Relating the pH reading to substances students know as acidic or basic, and further demonstrating what happens to the pH with tenfold dilutions, would aid in the students’ understanding of the concept.

12. Discuss the importance of maintaining pH in different regions of the body. Use pH values of blood and gastric juice to illustrate two different environments in the body, and explain how enzymes in one area may not work in another area.

Key point: Explain how chemical reactions and therefore cell functions do not occur if the environmental conditions where the reactions are to take place are outside the optimal and normal pH range for the particular chemicals to interact. This concept will be important later when discussing the respiratory buffer system in Chapters 13 and 15.

13. Construct a flowchart to help students identify molecular formulas for carbohydrates, lipids, and proteins. For example, if H:O = 2:1, the molecule is a carbohydrate. If there is mostly carbon and hydrogen and relatively little oxygen, it is probably a lipid. If there is nitrogen, along with carbon, hydrogen, and oxygen, most likely it is a protein or protein derivative. Then, put cutout pictures of various examples of carbohydrates, lipids, or amino acids on the board and ask students to classify them using the chart.

Key point: It is important to help students visualize organic compounds and their component parts. This will be particularly relevant later when students begin analyzing anabolism and catabolism.

14. Create ball-and-stick models or Zometool models to create monosaccharides, amino acids, and ionic compounds such as NaCl. Demonstrate synthesis, decomposition, and exchange reactions between the molecules.

Key point: Visual demonstration of the major reactions between molecules makes the interactions and processes tangible to students.

15. Discuss why proteins are important in the body, both as structural components and for their functional roles in physiological processes.

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Key point: Because proteins account for over 50 percent of organic matter in the body, it is valuable for students to understand the wide variety of functions that proteins play, from formation of enzymes to construction of body substances.

16. Discuss the role of enzymes in catalyzing reactions. Explain that enzymes work in a lockand-key method. The particular three-dimensional shape (active site) of the enzyme determines what substrate it will “fit” with chemically. Note that the “key” is not used up on a single reaction but can, in fact, be used over and over.

Key point: Visualizing the three-dimensional shape of enzymes helps students understand what happens when proteins (enzymes) are denatured, such as when body temperature is excessively elevated. Without intact binding sites, enzymes cannot perform their designated function.

17. Adipose tissue cells shrink or swell like sponges, depending on how much fat (triglyceride) is deposited within them. Fat represents stored “potential energy” and is mobilized into the bloodstream where it travels to skeletal muscles and is utilized for energy during exercise. Future chapters will build on this information.

Key point: Fat tissue is not metabolically active tissue, whereas skeletal muscle is. Thus, the stored energy within the fat must first be mobilized into the bloodstream in order to travel to other cells, such as skeletal muscle, to be used for energy.

Classroom Demonstrations and Student Activities Classroom Demonstrations 1. Demonstrate the classic static electricity experiments to allow students to visualize positive and negative charges and electron movement. Take a balloon and rub against your or a student’s hair. Then show how the balloon sticks to the wall. Explain how electrons are transferred from hair to the balloon, and how the rubbed hairs have a positive charge after electron loss and repel each other. The negatively charged balloon can then attract positive charges on the wall and therefore stick.

2. Demonstrate to the students how the amount of energy increases in atoms that have more electrons (and more electron orbitals). Under a fume hood, add small particles of lithium, sodium, and potassium to water in a glass beaker or Petri dish. Students can observe the length of time before the substance reacts, how long it reacts, and how bright the flame will be, depending on the number of electrons each element has in its orbitals.

3. Use the periodic table of elements to show the ionic bonding of sodium and chlorine to form salt. Have the students then diagram the ionic bonding of potassium chloride, potassium bromide, and similar salts, using the periodic table as a guide. Then use the periodic table to show the covalent bonding of carbon and methane. Have the students then diagram other organic compounds, using the periodic table as a guide.

4. Go through the periodic table, emphasizing the difference between the atomic number (number of protons and, also indirectly, number of electrons) and the atomic mass number (the sum of protons and neutrons). Point to various elements and ask how many protons, neutrons, and electrons make up the element in question. ..

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5. Demonstrate hydrogen bonding with a surface tension demonstration. Carefully place a paper clip on the surface of the water in a container and have it float, but then touch the water to make the paper clip sink, showing the fragile nature of the hydrogen bonding in the water.

6. Create ball-and-stick models or Zometool models of monosaccharides, amino acids, and ionic compounds such as NaCl. Demonstrate synthesis, decomposition, and exchange reactions. Then have students in small groups also go through synthesis, decomposition, and exchange reactions with preconstructed molecules. The concept of reactants and products can also be discussed in this exercise.

7. Create models of primary structure proteins. Combine these to make secondary structure proteins. Use those same models to demonstrate formation of tertiary and quaternary proteins.

8. Blow into a basic pH solution (e.g., diluted bleach) with phenolphthalein added with a straw and have students observe the color change of the solution from pink to clear due to the increase in acidity from the CO2. Some pH paper can be used to measure the pH of the solution before and after air is exhaled through the straw into the solution. Students can hypothesize what reaction is taking place, and drawing out the chemical reaction here would help with conceptualization.

9. Take some HCl and/or NaOH solution and measure the pH. Do tenfold serial dilutions and take pH measurements to visually show students how a tenfold difference translates to a change in pH of 1.

10. Spill some table salt from a salt shaker onto a table and balance the salt shaker on a grain of salt. Use this demonstration to discuss ionic bonding results in a crystal conformation that provides a linear plane to balance the shaker.

11. Use a Slinky® toy to demonstrate denaturation of an enzyme. Tie colored yarn on the Slinky at two sites that are widely separated, and then coil and twist the Slinky upon itself to bring the two pieces of yarn next to each other. Identify the active site where the yarn pieces are located. Then remind students that when the hydrogen bonds holding the enzyme (or functional protein) in its specific three-dimensional structure are broken, the spherical structure (and the active site) is destroyed, by allowing the Slinky to resume its helical shape. (This is best done when protein and enzyme structure has been discussed.)

12. Bring small, uniformly sized pieces of raw and cooked (either through heat or acid immersion) liver in individual test tubes. Pour hydrogen peroxide into both test tubes and have students observe the different results. This experiment illustrates the concepts of catalase enzyme conversion of hydrogen peroxide into oxygen and water in the uncooked (non-denatured) liver, and how denaturation affects structure, and therefore function, in the cooked liver.

13. Use or create a three-dimensional model of a portion of DNA and RNA. Demonstrate DNA’s units and overall structure. Have students search out similarities and differences with RNA while looking at both models, and have them fill in a chart or write the characteristics on the board.

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1. Have the students draw Bohr models of the elements most important to organic chemistry to clarify their understanding of the arrangement of electrons in shells.

2. Have the students draw electron dot models (Lewis structures) of various molecules to help further their understanding of ionic and covalent bonds.

3. Put a chair at the front of the room and have students come up and demonstrate the fixed pathway an electron would take in the planetary model versus the area of probability of where the electron would be in the orbital model to emphasize the difference between the two models.

4. Have students go through chemical equations of such molecules as NaCl. Have them write out synthesis of NaCl from Na+ and Cl−, and ask them to explain what the + and − signs mean. Ask which side designates the reactant and product in the equation, and how the direction of the arrow is significant. Then have the students go through the decomposition reaction of NaCl. Finally have students work through an exchange reaction with NaCl and KOH. 5. Have students build polysaccharides and polypeptides to illustrate synthesis reactions, then discuss how digestion leads to decomposition reactions, and then have students break down the polysaccharides to monosaccharides and polypeptides to amino acid components.

6. Have students conduct a calorimetry experiment to burn various snack foods (e.g., candy bar, chips) of equal mass and measure water temperature, and compare the results to the package nutrition labels to illustrate chemical energy in the form of calories.

7. Have students make cheese using citric acid, milk, and the enzyme rennet. Kits are available from education supply companies. Discuss how enzymes work.

8. Have students extract DNA from fruit, such as bananas or strawberries, so they can visualize the genetic material.

9. Bring students to an imaging lab where they can see examples of radioisotope use in medicine, and talk to a technologist and/or doctor about nuclear medicine.

10. Have students investigate why fat-soluble vitamins should be taken after a meal, while water-soluble vitamins do not need to be but should be taken with plenty of water.

11. Have students investigate why different pharmaceuticals, such as antibiotics, have different routes of administration due to their bioavailability and associated biochemical processes.

12. Provide Internet resources for students to watch “everyday chemistry” videos such as those at the following sites: • TED TALK 25 Chemistry Experiments www.youtube.com/watch?v=bOuEJf8Dr_4 • www.ocw.mit.edu/high-school/chemistry/demonstrations/videos/colorful-indicators • www.iowa.pbslearningmedia.org/resource/nvcol-sci-biolumine/wgbh-novacreatures-of-light-the-chemistry-of-bioluminescence/ • www.ocw.mit.edu/high-school/chemistry/demonstrations/videos

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Have students take videos or pictures of themselves doing these science experiments, or provide necessary equipment and supplies during class/lab time to reproduce the experiments in small groups.

Media See page 164 for a listing of media distributors.

1. The Atom Revealed (FHS: 50 min., 1993, VHS, DVD). Journeys into the atomic structure of substances that make up our world.

2. Chemical Bonding (FHS: 18 min., 2000, VHS, DVD, 3-year streaming webcast). From Chemistry: The Standard Deviants Core Curriculum, this video presents Lewis structures and the Octet Rule and its exceptions.

3. Double Helix (FHS: 108 min., 1987, VHS, DVD, 3-year streaming webcast). Hollywoodstyle film (starring actor Jeff Goldblum) that captures all the drama of the discovery of DNA. 4. Jurassic Park (127 min., 1993, VHS, DVD). A fictional story of how a wealthy entrepreneur creates a theme park featuring living dinosaurs created from prehistoric DNA. Scientifically sound arguments lead to interesting class discussions on the possibility of dinosaur cloning today, and the resulting ethical and ecological ramifications of bringing back extinct species.

5. Unlocking the Secrets of Life (FHS: 50 min., 1993, DVD). Presents the atomic structure of living things, showing how DNA governs the manufacture of proteins.

6. Greatest Discoveries with Bill Nye: Chemistry (Discovery Education, 45 min., 2005, DVD). Bill Nye discusses elements, molecules, and organic compounds, as well as the periodic table, and the application of these elements to pharmacology.

7. Nova: Hunting the Elements (PBS: 120 min., 2012, DVD). Introduction to chemistry with emphasis on the periodic table.

8. Chemistry of Life (Khan Academy, Web education). Tutorial of chemistry concepts important for biology. www.khanacademy.org/science/biology/chemistry--of-life 9. Unit 2: Chemistry of Life (Bozeman science, Web education) Video series on chemistry concepts that are essential for physiological processes. www.bozemanscience.com/biology-main-page 10. Chemistry of Life (HHMI BioInteractive, Web education). Video collection of chemistry topics related to human anatomy and physiology. www.hhmi.org/biointeractive/chemistry-life

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CHAPTER

3

Cells and Tissues

Chapter Summary Chapter 3 is the transition chapter between microscopic and macroscopic anatomical study.

Students are asked to examine the microscopic structure of individual cells, and subsequently combine them to form body tissues that perform specialized functions.

First, the discussion of the four elements that are found in all cells continues from Chapter 2. The cell theory, which emphasizes the cell as the fundamental building block of life, is then introduced to the students. The discussion moves to the anatomy of a generalized cell, which contains all of the features commonly found in mature human cells. The rationale of starting with a generalized cell is to allow students to gain a clear understanding of the three major regions of the cell and the organelles and structural components within them. The generalized cell combines features of different types of body cells. Note that each individual body cell may have some of these structures and not others, depending upon the function of that cell. Specializations of the plasma membrane are then covered; again, it is important to emphasize to the students that not all cells have these structures. A discussion of cell diversity follows a presentation of the anatomical structure of the cells’ component parts. This is the point at which students can differentiate between a generalized or nonspecialized cell and a specific cell (i.e., they begin to understand the similarities as well as the necessary anatomical differences between blood cells, bone cells, etc.). Cell physiology is presented next, with an explanation of both active and passive processes for transport of substances across the membrane. Here there is another connection with Chapter 2, where Na+ and K+ are revisited and their roles in solute pumping are explained, thus reiterating the connection between chemistry and physiology. A discussion of cell division then follows. A brief explanation of protein synthesis and the role of genes in DNA transcription and translation is then presented, along with the phases of mitosis so that students are given an overall picture of how transmission of genetic information during cell replication is carried out.

The final section of this chapter presents body tissues and their functions. Epithelial, connective, muscle, and nervous tissues are differentiated, followed by an overview of the developmental aspects of cells and tissues.

Suggested Lecture Outline Part I: Cells (pp. 60–86) I. 3.1 Overview of the Cellular Basis of Life (pp. 60–61) II. 3.2 Anatomy of a Generalized Cell (pp. 61–74) A. 3.2a The Plasma Membrane (pp. 61–63)

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1. Fluid Mosaic Model 2. Cell Membrane Junctions B. 3.2b The Nucleus (pp. 63–64) 1. Nuclear Envelope 2. Nucleolus 3. Chromatin

TEACHING TIP Allow for extra lecture time for this chapter. There are four main sections that should be allowed enough time to be covered due to the breadth of information.

The first three sections are (1) the structure and function of the cell and its organelles, (2) the processes of membrane transport, and (3) DNA replication and cell division. These concepts are usually novel to the students and should be explained more in depth, as they form the foundation of physiological processes in subsequent chapters. The fourth section addresses the classification and location of the various tissue types found in the body, which is learning intensive as well.

C. 3.2c The Cytoplasm (pp. 65–69) 1. Cytosol and Inclusions 2. Organelles a. Mitochondria b. Ribosomes c. Endoplasmic Reticulum d. Golgi Apparatus e. Lysosomes f. Peroxisomes g. Cytoskeleton h. Centrioles D. 3.2d Cell Extensions (pp. 69, 72) 1. Cilia and Flagella 2. Microvilli E. 3.2e Cell Diversity (pp. 72–74)

III. 3.3 Cell Physiology (pp. 74–86) A. 3.3a Membrane Transport (pp. 74–80) 1. Passive Processes: Diffusion and Filtration a. Diffusion b. Filtration 2. Active Processes a. Active Transport b. Vesicular Transport

MEDIA TIP Voyage Inside the Cell (FHS: 15 min., 1999). With computer-generated images and instructive narrative, the viewer is taken on a journey inside a living cell.

B. 3.3b Cell Division (pp. 80–83) 1. Preparations: DNA Replication 2. Events of Cell Division a. Mitosis b. Cytokinesis C. 3.3c Protein Synthesis (pp. 83–86) 1. Genes: The Blueprint for Protein Structure 2. The Role of RNA 3. The Process of Protein Synthesis a. Transcription b. Translation

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I. 3.4 Epithelial Tissue (pp. 86–91) A. 3.4a Hallmarks of Epithelium (pp. 86–87) B. 3.4b Classification of Epithelia (pp. 87–91) 1. Simple Epithelia a. Simple Squamous Epithelium b. Simple Cuboidal Epithelium c. Simple Columnar Epithelium d. Pseudostratified Columnar Epithelium 2. Stratified Epithelia a. Stratified Squamous Epithelium b. Stratified Cuboidal and Stratified Columnar Epithelia c. Transitional Epithelium 3. Glandular Epithelium

II. 3.5 Connective Tissue (pp. 91–96) A. 3.5a Hallmarks of Connective Tissue (pp. 91–92) B. 3.5b Extracellular Matrix (p. 92) C. 3.5c Types of Connective Tissue (pp. 92–96) 1. Bone 2. Cartilage 3. Dense Connective Tissue 4. Loose Connective Tissue a. Areolar Connective Tissue b. Adipose Connective Tissue c. Reticular Connective Tissue 5. Blood

III. 3.6 Muscle Tissue (pp. 96–98) A. 3.6a Skeletal Muscle (p. 96) B. 3.6b Cardiac Muscle (p. 96) C. 3.6c Smooth Muscle (p. 98)

IV. 3.7 Nervous Tissue (p. 98) V. 3.8 Tissue Repair (Wound Healing) (pp. 98–100) Note: For a list of Key Terms for this chapter, please go to Mastering A&P > Study Area > Additional Study Tools > Key Terms > Chapter 3.

Learning Objectives

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3-1

Name and describe the four concepts of the cell theory.

3-2

List four elements that make up the bulk of living matter.

3-3

Define generalized cell.

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3-4

Identify on a cell model or diagram the three major cell regions (nucleus, cytoplasm, and plasma membrane).

3-5

List the structures of the nucleus, and explain the function of chromatin and nucleoli.

3-6

Describe the chemical composition of the plasma membrane, and relate it to membrane functions.

3-7

Compare the structure and function of tight junctions, desmosomes, and gap junctions.

3-8

Identify the organelles on a cell model or describe them, and indicate the major function of each.

3-9

Apply the principle of complementarity to different cell types by comparing overall shapes, internal structures, and special functions.

3-10 Define selective permeability, diffusion (including simple and facilitated diffusion and osmosis), active transport, passive transport, solute pumping, exocytosis, endocytosis, phagocytosis, pinocytosis, hypertonic, hypotonic, and isotonic.

3-11 Describe plasma membrane structure, and explain how the various transport processes account for the directional movements of specific substances across the plasma membrane.

3-12 Briefly describe the process of DNA replication and of mitosis. Explain the importance of mitotic cell division.

3-13 Describe the roles of DNA and of the three major varieties of RNA in protein synthesis.

3-14 Name the four major tissue types and their chief subcategories. Explain how the four major tissue types differ structurally and functionally.

3-15 Give the chief locations of the various tissue types in the body.

3-16 Describe the process of tissue repair (wound healing).

Resources for Teaching Online Discussion Board Topic: Homeostatic Imbalance—Scar Tissue In the textbook on page 100, the Homeostatic Imbalance section explains that scar tissue is strong but cannot take over the function of the original tissue that was replaced. Engage your students by using the following discussion questions in lecture or by posting them to the discussion board on your course management system.

Discussion Questions 1. What are some common treatments for removing, or making less evident, scar tissue on skin? What are the proposed mechanisms on how these treatments would work?

2. Discuss stem cell therapy as a method of regenerating areas of injury that normally would be replaced by scar tissue, such as the brain or heart. What is the current status of research in this area?

3. Discuss somatic cell reprogramming with transcription factors and microRNA for cardiac tissue regeneration in animals and humans.

4. What is the treatment for scar tissue in soft tissue areas around joints and ligaments (contractures)?

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Potential Student Responses: 1. Laser scar removal with non-ablative and ablative fractional lasers (either stimulating collagen growth at the corneum level or minor “rewounding” of skin through heat application to produce a more uniform healing and thus reduction of scar, respectively), vitamin E treatment (because it is the main lipid-soluble antioxidant and can help in cell membrane stabilization, it is thought to be a good treatment for alleviating scar appearance; however, there is no research to support this in humans), silicone sheet (effective, but exact mechanism not known; possibly promotes regeneration by keeping area hydrated and/or decreasing proinflammatory cytokines in the area), and scar revision surgery (with skin flaps, skin grafts, or z-plasty done at the area of damage).

2. This question may generate some bioethics discussion as well as current ongoing advances in research. With study results, relay to the students that what works in an animal model may or may not work in humans.

3. This area of research has been effectively pursued in rodent models, where fibroblasts have been coaxed into cardiomyocyte-resembling cells, rather than scar tissue after myocardial infarctions. Scientists have been successful at replicating this procedure in the laboratory using human cells in a study conducted by Harvard Medical School and collaborators, and they hope this technology eventually can be used to create cardiac muscle patches for areas of damage and, eventually, an entire heart to be used in patients.

4. Physical therapy (stretching), surgery to release contracture.

Investigate Online Take learning a step further by searching for relevant research articles on the web. Visit science websites, such as those listed below, and begin by searching for key terms such as scar treatment, wound healing, scar therapy, stem cell therapy, hypertrophic scar, keloid scar, skin scar, and contracture and see how what you’re learning in the course applies to science and medicine today. www.sciencedaily.com www.scientificamerican.com www.the-scientist.com www.ncbi.nlm.nih.gov/pubmed www.aad.org www.plasticsurgery.org

Study Tips Direct students to the Study Tips feature located in the front of the book.

Mastering A&P Numerous items from Mastering A&P can be demonstrated in class, assigned as homework, or encouraged as study materials. These include practice tests and quizzes, animations and videos,

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Interactive Physiology (IP), Dynamic Study Modules, Audio Journeys, Practice Anatomy Lab (PAL), PhysioEx, flashcards, glossary, key terms, and more.

Interactive Physiology (IP) The following sections of Interactive Physiology are relevant to this chapter: Tissues IP Animation: Tissues

PhysioEx10.0[PM: Please check the comments and update ] The following sections of PhysioEx10.0 are relevant to this chapter:

Video of PhysioEx Lab Experiments: Cell Transport

Exercise 1: Cell Transport Mechanisms and Permeability

Animations and Videos The following animations and videos are relevant to this chapter:

A&P Flix: Mitosis; Membrane Transport; DNA Replication

BIO Flix: Protein Synthesis

Get Ready for A&P Video Tutors > General Cell Structure; Cell Membrane Structure; Diffusion; Osmosis; The Cell Cycle

Histology Videos > Areolar Connective Tissue; Dense Irregular Connective Tissue; Dense Regular Connective Tissue; Hyaline Cartilage; Pseudostratified Columnar Epithelium; Simple Columnar Epithelium; Simple Cuboidal Epithelium; Simple Squamous Epithelium; Stratified Squamous Epithelium; Transitional Epithelium

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The following sections of PAL3.1 are relevant to this chapter:

Histology > Cytology (cell division); Epithelial Tissue; Connective Tissue; Muscle Tissue; Nervous Tissue

Lecture Hints 1. Discuss the four main concepts of the cell theory with the students. Connect the concept of hierarchical organization of the body and where cells fall into this hierarchy. Also relate the concept of how structure determines function, even at the subcellular level.

Key point: Introducing the chapter with the cell theory is a nice segue from Chapter 2, the chemistry chapter, where atoms that combine into molecules are the building blocks of the cell. The cell is then introduced as the smallest building block of life, so the hierarchical organization introduced in Chapter 1 also continues. Finally, there is a nice tie-in again with the principle of complementarity of structure and function.

2. Emphasize that the cell described in this chapter is a generalized cell, which means it is a representation of a cell that combines features of different types of body cells. Of course, in reality, the actual somatic cells are variants of this generalized cell model. Mature red blood cells, for example, are anucleate and shaped like biconcave discs, while skeletal muscle cells are multinucleate and elongated, and neurons are uninucleate with branching processes emerging out of the cell body. The principle of complementarity again is evident, where it is the specialized structure of these cells that provides the ability to perform specific life-sustaining functions.

Key point: It is important for students to first understand the variety of components found in cells. From there, students begin to understand that all cells have some of the components, but few cells have all the components, and that the cell’s structure reflects its function. Relate to students that overall health of a cell is dependent on the weakest link in the chain, and that malfunctioning of one critical organelle can cause the entire cell to die.

3. Differentiate between the similar sounding “C” words of structures involved in cell division—centrioles, centromeres, chromatids, chromatin, and chromosome—as students are frequently confused by the terminology. Also stress to students that mitosis involves division of the cell nucleus and that serious mutations can result when any of the phases (prophase, metaphase, anaphase, and telophase) do not progress properly.

Key point: Chromatin contains DNA and is present under conditions where the cell is not dividing. When the cell is ready to divide, the chromatin condenses and becomes a chromosome. Each chromosome is actually made up of two chromatids (two halves of the “x” shape that we envision chromosomes to have), because DNA replication has already taken place in interphase. The centromeres hold the chromatids together, while the

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centrioles direct the assembly of the mitotic spindle upon which the chromosomes migrate during anaphase.

4. Give a brief explanation of mitosis to help students understand that mitosis is the method by which a body (somatic) cell constantly produces identical daughter cells such as during injury repair or growth.

Key point: Cell division is essential for body growth and tissue repair. Although we study the phases of mitosis as separate events, mitosis is actually a continuous process, with one phase merging smoothly into the next.

5. Discuss cancer as mitosis “gone wild.” Refer to the “A Closer Look” box in the chapter for more discussion on this homeostatic imbalance. Also, discuss which cells do not become cancerous.

Key point: Once students understand that all body cells have a limited life span and that most need to continuously replace themselves, they begin to understand that an imbalance in the replication process can have devastating effects. In cancer, the proliferation and spread of malignant cells in the body can disrupt the normal functioning of other tissues and organs. Use the discussion of cancer to reinforce the concept of the cell cycle.

6. Teach students the mnemonic device “I Passed My Anatomy Test” to help them learn that interphase precedes the four phases of mitosis. Point out that a cell in interphase carries out normal cellular functions and prepares to divide. Although the stages of the cell cycle are described as discrete events, students should see that they represent a continuous process. Video segments that show the cell cycle in action will help students to better visualize this process.

Key point: Explain that cells live out the bulk of their lives in interphase, which is not a dormant phase, but rather the time frame within which the DNA content of a cell must precisely double. Cells then form two identical daughter cells by going through prophase, metaphase, anaphase, and telophase during mitosis. Emphasize to students that the phases of mitosis follow one after another in a continuous flow, but that they are presented in segments for better understanding.

7. Outline the process of DNA replication, which takes place during interphase.

Key point: Introducing the steps of transcription and translation in protein synthesis is important for students to understand the molecular physiology of cell division preparation. This process will also help integrate organelle identity and the function of the specific organelles and structures involved in DNA replication. Although each organelle is introduced separately in the text, it is integral for students to be able to see the big picture and understand how the organelles work with one another, performing their specialized roles. This outline can be done at a very general level.

8. Discuss the various processes that take place in the interphase portion of the cell cycle.

Key point: Although the name interphase implies the “in between phase,” or the phase between mitotic divisions of the cell, there are a number of key processes that take place, and it is important to emphasize that, in fact, interphase comprises the majority of the length of time in one revolution of the cell cycle, where the cell undergoes normal development and cell type-specific functioning. There is always heavy emphasis placed on mi-

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tosis due to its multistep process, which can be complicated; however, students must understand that mitosis is just one small portion of the cell cycle.

9. Differentiate between intracellular and extracellular fluid. Explain that extracellular fluid, or fluid found outside the cell, is also called interstitial fluid because it is located in the spaces between the cells. Discuss how a buildup of this fluid following an injury or during chronic sedentary living would lead to edema.

Key point: Having a clear understanding of the location of body fluids will help students to understand the homeostatic mechanisms involved in fluid balance.

10. Discuss the concept of the concentration gradient and the idea that when molecules move down the gradient, they are involved in passive transport processes, whereas molecules moving up the gradient are involved in active transport processes.

Key point: The role of the concentration gradient in active and passive transport processes, and the role of ATP in these molecular movements, are significant concepts for students to master.

11. The terms hypertonic, hypotonic, and isotonic should be separated into their roots so that their meanings are immediately obvious to the student. For example, hypertonic means “excessive tension,” therefore, water is drawn into a hypertonic solution. Hypotonic, on the other hand, means “deficient tension”; therefore, water passes out of a hypotonic solution. Since isotonic means “equal tension,” an isotonic solution is homeostatically balanced.

Key point: It is important for students to have a clear understanding of these terms and their significance in the body’s water balance. The terms hypertonic, hypotonic, and isotonic can refer to either intracellular or extracellular fluid, so be specific. For this course level, it may be sufficient to focus on the extracellular environment. Also, be sure to emphasize the effect of the extracellular environment on cell tonicity.

12. Discuss the application of different intravenous solutions in health care. Identify various types of solutions as hypertonic, hypotonic, or isotonic (D5W, 1/2 NS, NS, LR, and D5NS, for example).

Key point: Presenting real-world applications helps students better understand the importance of these concepts. D5W is dextrose 5% in water, which becomes hypotonic in the body to raise total fluid volume, and 1/2NS 0.45% normal saline is also hypotonic for the same purpose. NS is 0.9% normal saline, which is isotonic to replace plasma volume due to fluid loss, and normal saline with electrolytes and buffer (isotonic) to replace fluid loss and restore pH balance. D5NS is hypertonic and is dextrose 5% in 0.9% saline to replenish fluids and calories.

13. Explain osmosis, or the diffusion of water, in detail. Students are frequently confused by the fact that water moves into an area of high solute concentration. Use the example of jerky to relate how the high concentration of salt draws water out of the meat cells by osmosis to produce jerky. Point out that it is easier for water molecules than for solutes to move across semipermeable membranes; thus, water’s role is to dilute the solution until equilibrium is reached. Water is a very polar molecule, enabling polar solutes to be dissolved within it.

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Key point: Being able to visualize the shift of fluids within the body is particularly necessary in understanding the activities of the urinary and cardiovascular systems. Water is absolutely essential to life as we know it, and the search for past or present life on other planets always focuses on the evidence of water.

14. Discuss the concept of a pressure gradient and compare it to a concentration gradient.

Discuss the concept of filtration and what occurs in the kidneys due to hydrostatic pressure.

Key point: A pressure gradient occurs from an area of high to low, but instead of high concentration to low concentration, it is where fluid travels from an area of high fluid (hydrostatic) pressure to an area of low fluid pressure. Water and its dissolved solutes travel out of the capillaries where the hydrostatic pressure is great and enter the kidney tubules where the hydrostatic pressure is lower. This is the basis for the formation of urine.

15. Present phagocytosis (cell eating) and bulk-phase endocytosis (pinocytosis, or cell drinking) by first identifying their word parts. Explain that both processes are part of endocytosis, where the cell brings substances inside, into the intracellular environment. Be sure that students understand that bulk-phase endocytosis is not just taking in water but is, in fact, a means of bringing in extracellular fluid, including the dissolved substances within that fluid.

Key point: Students sometimes confuse cell drinking with simple water intake, and it is important to clarify that the process is more complex than that.

16. Show micrographs of various tissues and point out the similarities and differences so that students can identify the tissue types based on their characteristics.

Key point: The various tissue types appear confusing at first and tend to intimidate students initially, but they become clearer as their key characteristics are noted.

17. Relate to students that hyperplasia describes an increase in the total number of fibers within a body tissue or organ. Differentiate for students that hypertrophy describes the increase in size of existing cells, whereas atrophy describes the decrease in the size of existing cells, with neither hypertrophy nor atrophy describing any changes in the total number of fibers.

Key point: A weight lifter exhibits skeletal muscle hypertrophy during chronic strength training, whereas the reverse condition of skeletal muscle atrophy occurs when training load is reduced. Hyperplasia of skeletal muscle does not occur even during intense conditioning, although there is a possibility that athletes who dangerously abuse anabolic steroids may exhibit some hyperplasia.

Classroom Demonstrations and Student Activities Classroom Demonstrations 1. Use a cell model or pictures to demonstrate the various organelles and cell parts for the generalized cell.

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2. Draw a cell “shell” where students have to come up to the board and draw in an organelle. Have students also state the function of the organelles as they come up to draw them on the board.

3. Draw side-by-side diagrams of simple diffusion, facilitated diffusion, and active transport so that students can compare and contrast these processes.

4. Discuss the process of kidney dialysis as it relates to diffusion and filtering of the blood.

Bring in dialysis tubing for the students to pass around; alternatively, conduct a diffusion demonstration.

5. Illustrate the mechanics of the sodium-potassium pump for a good example of an active transport process. To make this more interactive, use props such as five folding chairs (for five students); open and close the chairs to illustrate the process of solute pumping (use three chairs for Na+ and two chairs for K+).

6. Draw a picture of a cell to show intracellular fluid versus extracellular fluid. For extracellular fluid, draw the different compartments—interstitial, plasma, and lymph—for students to understand how extracellular fluid compartments relate to one another.

7. Use microscope slides to show the differences between various cell/tissue types.

8. Using pictures, demonstrate how the different cell junctions, as well as membrane specializations (such as microvilli increasing surface area), help in the function of various cell types.

9. Use models of the events of mitosis or draw the phases of mitosis to support your class presentation of cell division.

10. Have students look at prepared microscope slides of animal (e.g., whitefish blastula) and plant (e.g., Allium root tip) cells undergoing various mitotic phases.

11. Use diagrams of RNA and DNA to illustrate similarities and differences.

12. List a string of nucleotides on the board. Indicate that the nucleotide sequence represents an original DNA sequence. With the students, walk through the corresponding mRNA sequence that would result from transcription. Next, use the genetic code to determine the polypeptide chain that results from translation. Note that a “transcript” is a copy of the message, and it remains in the same nucleotide language. Then point out that the mRNA transcript is “translated” into the language of proteins, consisting of amino acids instead of nucleic acids.

13. Provide models of nucleotides for students to disassemble and reassemble into various nucleotide sequences. Note that a change in even a single base pair may completely change the resultant protein. Use the example of sickle-cell anemia to illustrate this concept.

14. Discuss fluid replacement after varying degrees of exercise with hypertonic (e.g., Gatorade performance) versus isotonic (e.g., Powerade) versus hypotonic (e.g., Mizone) sports drinks versus water (hypotonic). Students may also bring up the topic of sports gels, and it should be emphasized that they are caloric replacements rather than fluid replacements.

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15. At the beginning of the lecture, place one or two drops of food coloring into a large beaker. Note the diffusion of the color throughout the class to emphasize how molecules go from an area of high concentration to an area of low concentration until equilibrium is met (uniform color in the beaker without mixing). Reiterate the lack of ATP use in this process.

16. Set up a simple osmometer before class and have students observe the fluid level in the tube from time to time. Put glucose solution in a dialysis sac and tie the sac tightly to a length of glass tubing. Secure the glass tubing to a ring stand with a clamp. The glucosecontaining dialysis sac should be immersed in distilled water in a beaker. Use this demonstration to support your discussion of osmosis and how knowledge of fluid dynamics is critical to health care.

17. Place slices of potato (French fry style) into (1) beaker of tap water and (2) beaker of high salt solution and let sit overnight. Demonstrate how the slices placed in the high salt solution are quite flexible because the high salt solution drew the water out of the potato by osmosis.

Student Activities 1. Have students label a picture of the generalized cell with the organelles and structures.

2. Have students create or fill out a chart of organelle functions.

3. Call out organs and their functions, and have students list organelles that should be found in the cells that comprise those organs.

4. Have students go to the board to draw out how a substance can be brought into the cell: endocytosis, pinocytosis, receptor-mediated endocytosis. Ask them to discuss the similarities and differences of these processes.

5. Have students create a fluid-mosaic model of the cell membrane out of various candies.

They can be creative, using lollipops with an extra stick as phospholipids, for example.

6. Have students look at several cell types and draw what they see. Ask them to identify all the structures they see. Point out similarities and differences, and ask them to guess the various functions based on structure, before revealing the cell identity.

7. Have students lightly scrape the interior of the cheek with a flattened toothpick and smear on a slide, then allow the slide to dry, stain it with methylene blue, and view it under the microscope.

8. Have students identify tissue types from verbal descriptions or pictures, such as simple squamous, stratified squamous, and so on. Have students explain what the first part of the nomenclature (simple or stratified) means—that is, number of layers of cells—and what the second part of the nomenclature (cuboidal, columnar) means—that is, shape of the cells at the apical surface. Alternatively, have students look at histology slides to deduce either identity and/or function of the tissue. This can be worked into the format of a game show, such as Jeopardy.

9. Have students link cutouts of base pairs, where the complementary nature of the nucleotide bases is emphasized.

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10. Provide students with a DNA template sequence and have them determine the complementary nucleotide sequence for the mRNA transcript. Then have the students use the genetic code to produce the amino acid sequence that is translated from the mRNA transcript. Have them identify the nucleus as the location for transcription and the cytoplasm for the events of translation.

11. Have students name any examples of diffusion, osmosis, and filtration they can think of from their daily lives.

12. Especially for online course delivery, students can use a virtual online microscope to study the phases of mitosis as well as the tissues of the body. One example is found at: www.ncbionetwork.org/iet/microscope/

Media See page 164 for a listing of media distributors.

1. A Journey Through the Cell (FHS: 20 min. each, 1997, DVD, 3-year streaming webcast).

A two-volume set that combines live-action footage, computer graphics, and animation to explore cell structure and function.

2. After Darwin: Genetics, Eugenics, and the Human Genome (FHS: 2 parts, 49 min. and 46 min., 1999, VHS, DVD, 3-year streaming webcast). Award-winning documentary about the history of genomic research, including the Human Genome Project, cloning, and gene patenting.

3. Cancer and Metastasis (FHS: 39 min., 1995, VHS, DVD, 3-year streaming webcast).

This video studies the biological processes by which cancer develops and metastasizes.

4. Double-Helix (FHS: 108 min., 1987, VHS, DVD, 3-year streaming webcast). Exceptional film (starring well-known actor Jeff Goldblum) that captures all the drama of the discovery of DNA. 5. Hand-Me-Down Genes: An Introduction to Genetics (FHS: 2 parts, 25 min. and 28 min., 1997, VHS, DVD, 3-year streaming webcast). A two-part series covering “How Genes Work” and “Family Patterns.”

6. Human Biology (FHS: 58 min., 1995, VHS, DVD). Twenty-one live-action video sequences provide an overview of human biology.

7. Human Body: The Ultimate Machine (CBS: 27 min., 2005, VHS, DVD). The body’s major systems are described through footage of surgical procedures, microphotography, and 3-D animation.

8. Voyage Inside the Cell (FHS: 15 min., 1999, VHS, DVD, 3-year streaming webcast).

With computer-generated images and instructive narrative, the viewer is taken on a journey inside a living cell.

9. Standard Deviants School: Biology (The Basics / The Cell / RNA / Cell Division & Metabolism) (SDS: 104 min., 2012, DVD). A humorous tutorial on various aspects of cell structure and function.

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10. Eukaryopolis - The City of Animal Cells (Crash Course: 12 min., 2012. , www.thecrashcourse.com/search?query=the+city+of+animal+cells). A brief explanation of the eukaryotic cell.

11. A Journey Inside the Cell (15 min., 2014) www.youtube.com/watch?v=dLDM2faHyRE An animation showing the inner workings of the cell.

12. Biology, Cell Structure: Nucleus Medical Media (7 min., 2015) www.youtube.com/watch?v=URUJD5NEXC8. Animation shows the structures of eukaryotic cells.

13. A Tour of the Cell: Bozeman Science (14 min., 2012). www.youtube.com/watch?v=1Z9pqST72is. Paul Anderson describes and illustrates a tour through the cell.

14. Phases of Mitosis: Bozeman Science (11 min., 2014). www.youtube.com/watch?v=mXVoTj06zwg. Paul Anderson describes the phases of mitosis.

15. From DNA to Protein (3 min., 2015). www.youtube.com/watch?v=gG7uCskUOrA. 3D animation shows an overview of the steps of transcription and translation.

16. Transcription and Translation: Bozeman Science (12 min., 2012). www.youtube.com/watch?v=h3b9ArupXZg. Paul Anderson explains the central dogma of biology.

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CHAPTER

4

Skin and Body Membranes

Chapter Summary Chapter 4 builds upon the cell and tissue information presented in Chapter 3, with a focus on skin and body membranes. Students now have an understanding of the similarities and differences between cells, and also have a working knowledge of the various types of tissues in the body. Continuing with the theme of increasing complexity of levels of organization, the next step is the combination of two or more tissue types to form an organ with specific functions, an example of which are membranes. The four types of membranes (cutaneous, mucous, serous, and synovial) are presented.

The next section of this chapter delves into the mechanics of the integumentary system, which students easily identify as their skin. Students will learn that skin, the largest organ of the body, has a multitude of functions. The structure of the skin is presented, detailing the layers and components of the epidermis, as well as the dermis. Determinants of skin color are discussed.

Accessory structures of the skin are discussed next. Cutaneous glands (sebaceous/oil and sweat/sudoriferous), hair and hair follicles, and nails are all presented. Finally, an overview of homeostatic imbalances affecting skin is outlined, including the effects of infections and allergies, burns, and skin cancers. The chapter closes with an explanation of the developmental aspects of the skin and body membranes, and students particularly enjoy learning about the skin’s aging processes and what they can do to delay that process.

Suggested Lecture Outline I. 4.1 Classification of Body Membranes (pp. 106–109) A. 4.1a Epithelial Membranes (pp. 107–108) 1. Cutaneous Membrane 2. Mucous Membranes 3. Serous Membranes

TEACHING TIP

B. 4.1b Connective Tissue Membranes (pp. 107, 109)

II. 4.2 The Integumentary System (Skin) (pp. 109–124) A. 4.2a Functions of the Integumentary System (pp. 109–110) B. 4.2b Structure of the Skin (pp. 110–115) 1. Epidermis 2. Dermis C. 4.2c Skin Color (pp. 115–116) D. 4.2d Appendages of the Skin (pp. 116–120) 37

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Review the definition of an organ, and how skin is considered to be an organ, to relate back to concepts introduced in Chapter 1. Discuss the tissue types that make up the cutaneous membrane, for example, and the functions of skin, to again emphasize complementarity of structure and function in this organ system.

1. Cutaneous Glands a. Sebaceous (Oil) Glands b. Sweat Glands 2. Hair and Hair Follicles a. Hairs b. Hair Follicles 3. Nails

MEDIA TIP Exposed ( 5 min.) impactmelanoma.org/wpcontent/uploads/2019/12/Exposed.mp4) Examines the problem of skin cancer from its roots in chronic overexposure to the sun with personal perspectives of melanoma survivors.

E. 4.2e Homeostatic Imbalances of Skin (pp. 120–124) 1. Infections and Allergies 2. Burns 3. Skin Cancer a. Basal Cell Carcinoma b. Squamous Cell Carcinoma c. Malignant Melanoma

III. 4.3 Developmental Aspects of Skin and Body Membranes (p. 124–126) Note: For a list of Key Terms for this chapter, please go to Mastering A&P > Study Area > Additional Study Tools > Key Terms > Chapter 4.

Learning Objectives 4-1

List the general functions of each membrane type—cutaneous, mucous, serous, and synovial—and give its location in the body.

4-2

Compare the structure (tissue makeup) of the major membrane types.

4-3

List several important functions of the integumentary system, and explain how these functions are accomplished.

4-4

When provided with a model or diagram of the skin, recognize and name the following skin structures: epidermis, dermis (papillary and reticular layers), hair and hair follicle, sebaceous gland, and sweat gland.

4-5

Name the layers of the epidermis, and describe the characteristics of each.

4-6

Name the factors that determine skin color, and describe the function of melanin.

4-7

Describe the distribution and function of the epidermal appendages—sebaceous glands, sweat glands, hair, and nails.

4-8

Differentiate among first-, second-, third-, and fourth-degree burns.

4-9

Explain the importance of the “rule of nines”.

4-10 Summarize the characteristics of basal cell carcinoma, squamous cell carcinoma, and malignant melanoma.

4-11 List several examples of integumentary system aging.

Resources for Teaching Online Discussion Board Topic: Homeostatic Imbalance—Acne

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In the textbook on page 116, the Homeostatic Imbalance section explains that acne is an active infection of the sebaceous glands. Engage your students by using the following discussion questions in lecture or by posting them to the discussion board on your course management system.

Discussion Questions 1. What is thought to cause acne? What causes some individuals to have mild acne and others to exhibit severe acne? Are there age- and sex-related differences?

2. What are the leading nonprescription treatments of acne?

3. What are the leading prescription/physician-administered treatments of acne?

Potential Student Responses: 1. Stress—when there are surges of hormones (puberty, menstrual periods, pregnancy; current research demonstrates that sebaceous glands can manufacture and react to stress hormones)—results in clogging of the pores with more sebum production and proliferation in the clogged pores of P. acnes, a bacterium normally found in skin. Genetics also appear to play a role. The incidence of acne emergence is roughly equal between the sexes, but cyclical surges of acne follow elevations of the hormone estrogen during the menstrual period in females, while in males there may be a correlation of androgens with more chronic acne. No scientific evidence exists that chocolate causes acne or that sunlight lowers the incidence of acne. Do not use astringents, masks, and so on; these tend to irritate the skin and make it more difficult to tolerate treatment. Do not pick, pop, or squeeze acne because it will irritate the area and exacerbate the symptoms.

2. Benzoyl peroxide is effective for P. acnes reduction and removal of dead, skin-clogging cells. Salicylic acid prevents abnormal shedding of skin that would clog pores.

3. Topical therapy such as retinoids and prescription-strength benzoyl peroxide, antibiotics, isotretinoin, and oral contraceptives are recommended by the American Academy of Dermatology (AAD). In addition, the AAD states that combining two or more treatments, as prescribed by a board-certified dermatologist, may be even more effective. It is important to avoid pregnancy during oral isotretinoin use, which is effective for moderate to severe acne that does not respond to other treatments.

Investigate Online Take learning a step further by searching for relevant research articles on the web. Visit science websites, such as those listed below, and begin by searching for key terms such as acne, comedones, acne treatment, and acne therapy and see how what you’re learning in the course applies to science and medicine today. www.sciencedaily.com www.scientificamerican.com www.the-scientist.com www.ncbi.nlm.nih.gov/pubmed www.aad.org

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Study Tips Direct students to the Study Tips feature located in the front of the book.

Mastering A&P Numerous items from Mastering A&P can be demonstrated in class, assigned as homework, or encouraged as study materials. These include practice tests and quizzes, animations and videos, Interactive Physiology (IP), Dynamic Study Modules, Audio Journeys, Practice Anatomy Lab (PAL), PhysioEx, flashcards, glossary, key terms, and more.

Practice Anatomy Lab (PAL)3.1: Including Mobile Flashcards The following sections of PAL3.1 are relevant to this chapter:

Anatomical Models > Integumentary System

Histology > Integumentary System

Additional Study Tools The following video is relevant to this chapter:

Focus on Careers > Medical Transcriptionist

Lecture Hints 1. Show slides of various types of skin sections and compare to the diagram of the skin in the text. Emphasize that the diagram is an idealized picture and that skin varies at different regions of the body with age, sex, and race, as shown in the slides.

Key point: It is often difficult at first for students to “see” all of the different structures found in skin when looking at actual cross sections, as compared to structures represented in diagrams. The more samples they see, the better their understanding of what they are seeing. Microscopic slides of various healthy and diseased skin tissues are not always as nice as the presentations in textbooks.

2. Students are always interested in discussing the skin as a thermoregulatory organ. Ask students to discuss changes in their skin on hot and cold days or when they have a fever.

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night or changing into a lightweight shirt on a hot day. Discuss the effects of alcohol consumption on skin color and body temperature regulation.

Key point: Skin is usually perceived as just a barrier against invading organisms. However, clearly it is also an excellent thermoregulator. Behavioral changes to accommodate temperature changes also help skin function in efficient thermoregulation.

3. Discuss the characteristics and locations within the body of the two classes of epithelial membranes.

Key point: The cutaneous membrane is really just another name for the skin. Students should be able to intuitively name its physical characteristics of being dry and found at the surface, exposed to air. On the other hand, the mucous membranes line body cavities, such as those of hollow organs, and are moist membranes that primarily function in absorption or secretion. The membranes may secrete mucus as in the respiratory or digestive organs, but this is not the case in the urinary system organs.

4. Discuss the fact that humans all have roughly the same number of melanocytes and that skin color is based on genetic determination of the activity of the existing melanocytes, not on numbers. There is increased melanin production (size and number of melanin granules) in those exposed to more UV radiation and decreased melanin production in those exposed to less UV radiation.

Key point: Students are often surprised by the fact that there are similar numbers of melanocytes among people of different ethnic groups, and that it is simply varied degrees of production of the different types of melanin that account for skin color differences. Point out the role of melanin in acting as a “natural sunscreen.” Discuss the fact that darkerskinned people have lower incidences of skin cancer. However, it must also be emphasized that sunscreen should still be applied, regardless of skin color. People of color, when diagnosed with melanoma, have a worse prognosis than Caucasians, as detection of the cancer is at later stages because early warning signs tend to be overlooked. Although melanin is protective, its emergence, as in a tan, is indicative of previous sun exposure and damage, and therefore there is a higher risk of cell damage/mutation in individuals with tans versus individuals without a tan.

5. Discuss all of the factors involved in skin color, including the amounts and kinds of pigment present, the amount of carotene present, the amount of oxygen bound to hemoglobin, and emotional stimuli.

Key point: It is important for students to understand that many factors are at play in the determination of relatively permanent and temporary skin color and that some of the factors are externally induced. Skin color is not solely due to melanin content.

6. Differentiate the types of sweat glands, pointing out that sweat produced by eccrine glands is primarily water, whereas sweat produced by apocrine glands contains fatty acids and proteins. Note that sweat produced by the latter type of sweat glands provides a food source for bacteria living on the skin, and it is a metabolic by-product of those bacteria, which accounts for the unpleasant odor associated with sweat. Sweat produced by eccrine glands is an odorless substance that actually inhibits bacterial growth.

Key point: Students usually don’t realize there are two distinct types of sweat glands producing two distinct products that have separate functions.

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7. Discuss what secretion forms fingerprints.

Key point: Students often assume fingerprints are from “the oils” on the fingers. They are surprised to learn that there are no sebaceous glands on the fingers; rather, it is eccrine gland secretion that forms fingerprints.

8. Discuss differences in hair types. Hair that has an oval shaft is smooth, silky, and wavy, whereas hair that is flat and ribbonlike is curly or kinky. Students enjoy learning about what makes their hair have the characteristics it has and appreciate the mechanisms involved in trying to change their hair type by “perming” and other methods. Have students examine normal-colored and artificially colored hair under a microscope.

Key point: This is an area students enjoy discussing, and it provides a valuable opportunity for the appreciation of genetic variety.

9. Use a partially deflated balloon (representing the serous membranes) and your fist (representing the body organ) to help students understand the terms visceral and parietal.

Punch a hand into the balloon: The portion that covers the fist represents the visceral portion, and the air inside the balloon is the serous fluid and the parietal portion. Point out that visceral refers to the viscera, or the organ itself, whereas parietal refers to the sac that the organ sits in. Compare directly to diagrams of visceral and parietal peritoneum, pericardium, and pleura.

Key point: It is important for students to understand that there are distinct coverings to the organs and that this pattern of having a visceral as well as a parietal covering will be found numerous times as we study various organs. Also have students understand that the visceral and parietal serosa are really one continuous membrane, much like a balloon.

10. As a point of interest, note that although vitamin D is produced in the skin and is converted from its inactive to active form by sunlight, it is activated by the kidneys. Functioning kidneys are key to vitamin D availability in the body; thus, premature infants with unstable kidneys are at risk for developing rickets and other related diseases.

Key point: This is a good opportunity to point out the interplay between body systems and to note their interrelationships in maintaining homeostasis.

11. In this chapter, students learn that burns are classified according to depth and/or amount of surface area affected. Emphasize that there are other factors to consider, such as the type of burn (electrical, chemical, etc.), area of the body burned (chest, face, hands, etc.), and the person’s age. Include the value of stem cells found in the accessory skin organs for healing and tissue regeneration. Also discuss skin grafting and other current treatments for severe burns.

Key point: When discussing the consequences of serious burns, refer to the functions of the integument. Loss of skin leads to loss of protection against infection, loss of water, and so on.

12. Discuss sunburn in relation to the degree of burn and the long-term potential for skin cancer. Most students have had at least one serious bout with sunburn and are eager to know the implications.

Key point: Sunburn that involves blistering is a second-degree burn that requires treatment to prevent infection. Also use this discussion to again differentiate second-degree burns from first-degree, third-degree, and fourth-degree burns. ..

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13. There are over a thousand different disorders related to homeostatic imbalances of the skin. It is helpful to discuss some of the more common skin disorders, such as acne, athlete’s foot, cold sores, and psoriasis, as well as some of the exanthematous skin eruptions, including chicken pox and measles.

Key point: The significance of homeostatic imbalance related to the skin is often quite clear to students because many have had some form of skin disorder during their lifetime.

14. Discuss the ABCDE rule of malignant melanoma and have students talk about their own observations or experiences.

Key point: Students are familiar with this subject due to media attention, and selfassessment of skin condition using the ABCDE rule is one that is tangible and accessible to the students and serves as a good introduction to techniques used in the medical field.

Students often assume this rule is for all skin cancer; therefore, it is important to emphasize it is only for melanoma and to use the opportunity to describe the differences between basal cell and squamous cell carcinoma.

Classroom Demonstrations and Student Activities Classroom Demonstrations 1. Demonstrate the structure of the skin using a three-dimensional model.

2. Discuss tattooing, and use it as a model to emphasize learning the layers of the epidermis and dermis. Use a cross-sectional picture or model of skin structure and show where the ink initially is deposited, where it is distributed, and why tattoos can fade over time.

3. Discuss the various mechanisms of blistering—for example, sunburn blisters versus pressure/friction blisters versus fracture blisters.

4. Show a histology slide of skin or the scalp and identify various structures such as eccrine glands, hair follicle, arrector pili, and sebaceous glands.

5. Use a human torso model to show the body location of the mucous and serous membranes.

6. Show pictures of selected skin disorders; discuss causes and treatments.

7. Bring a paramedic into the classroom to discuss the treatment of burn injuries.

Student Activities 1. Have a small fan operating. As students file into the classroom, spray their arm or hand with a clean spray bottle filled with water. Ask them to describe their sensations as the water evaporates and to explain why evaporation of water (sweat) from the skin surface is important to body homeostasis. Stress that calories of heat are only released from the body as liquid sweat evaporates.

2. Indicate to the class that many animals (e.g., snakes, insects, and lobsters) shed their skin periodically. Ask them to comment on how humans compare in this aspect (discuss the composition of dust found in a home).

3. Student assignment for class discussion: 43

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a. Look up minoxidil as a current drug treatment for baldness. b. Discuss current skin treatment products and treatment services that are advertised as effective for anti-aging. What are common rationales by companies that market these products and services, regarding how wrinkles disappear? Discuss whether such products and services are effective. c. Discuss how bimatoprost (Latisse is one brand) was discovered to lengthen eyelashes. d. Discuss how the botulism toxin (used in Botox) was discovered to be effective against wrinkles. See the relevant discussion in “A Closer Look” in your textbook chapter for therapeutic uses other than wrinkle removal. e. Find references in current journals to the damaging effects of sunlight on the skin, and be prepared to describe the difference in the A and B types of UV rays relative to skin damage. Discuss what types of UV rays are used in tanning beds. f. Examine the effects of using various types of sunscreen; those that function as chemical versus physical protectants, including the meaning of SPF values and the duration of sunscreen’s effectiveness. g. Discuss hair transplant surgery techniques: follicular unit strip surgery (FUSS) or follicular unit extraction (FUE). Which would you choose and why?

4. Show students a picture of a heavily wrinkled person. Ask them to list all of the factors that might have contributed to the skin deterioration. Discuss the research that led to the use of retinoic acid for the treatment of photo-aged skin.

5. Provide magnifying lenses. Have the students use them to examine their skin and the mucosa of a classmate, and then describe important differences visible in these two types of covering epithelia.

6. Provide small glass plates and instruct students to observe the change in the color of their skin while pressing the heel of their hand firmly against the glass. Ask them to explain the reason for the color change and what would happen to their skin cells if the pressure were prolonged.

7. Demonstrate the effectiveness of different SPF factor sunscreens by preparing a transparency with a thin layer of various sunscreens side by side. After the sunscreen layers have dried, have students go outside and place UV detecting beads or UV meters (can be purchased at Carolina Biologicals or other educational supply companies) under the transparency to have students observe the protective effects of the sunscreens.

8. Student assignment for class discussion: Look up the signs and symptoms of basal cell carcinoma, squamous cell carcinoma, and malignant melanoma for class discussion. Have students discuss which layer of epidermis is initially affected in each type of skin cancer.

9. Student assignment for class discussion: Have students research and report on FDA regulations for the classification of cosmetics and drugs.

10. Look at shafts of hair and shavings of nails under a microscope. Point out that even though these substances are dead, they are a good indicator of health or disease caused by dietary insufficiency or other homeostatic imbalances.

11. Discuss how hair and nails are used in forensic analysis.

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Media See page 164 for a listing of media distributors.

1. Skin (FHS: 20 min., 1995, DVD, 3-year streaming webcast). From The New Living Body series, this video shows the detailed internal structure of the skin using high-quality computer graphics.

2. Tissue Engineering: Custom-Made Organs on Demand (FHS: 22 min., 1999, VHS, DVD, 3-year streaming webcast). Tissue engineering is explored, including applications in burn victims and diabetics.

3. Skin Cancer: How Skin Cancer Develops (Mayo Clinic: 2 min., Web education, www.mayoclinic.org/diseases-conditions/skin-cancer/multimedia/melanoma/vid20084739). General introduction to skin cancer, with emphasis on melanoma.

4. The Integumentary System Part 1 www.youtube.com/watch?v=Orumw-PyNjw (9 min.) and part 2 www.youtube.com/watch?v=EN-x-zXXVwQ (10 min.). Easy-to-understand explanation of the anatomy and physiology of the integumentary system.

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CHAPTER

5

The Skeletal System

Chapter Summary The skeletal system is one of the body systems that students most enjoy studying: They can easily identify the system in their own bodies, and many students have rudimentary knowledge about various bones through their own sports activities or past injuries. Naming the bones is initially a challenge; however, skeletal nomenclature then rapidly becomes a source of confidence as students develop their identification skills. Learning about the dynamic nature of bones, and in particular their role in hematopoiesis, the rich nerve supply and vascularization, as well as the constant remodeling that takes place, also dispels many preconceived ideas that students may have about bones resembling dead twigs or remaining unchanged over time.

This chapter begins with an overview of the many functions of bones. Next, bones are classified into one of four groups, depending on their anatomy, specifically the general shape of the bone: long, short, flat, or irregular. Each bone group is made up of different proportions of two types of osseous tissue—spongy and compact bone—to carry out the functions of support, movement, protection, storage, and hematopoesis. This again reflects the pervading theme of complementarity of structure and function. The macroscopic (gross) anatomy of a long bone, as this is the most prevalent bone group in the body, provides a conceptual image of bone structure, and the microscopic anatomy helps students to begin to understand the complexity of bone and the reasons for its dynamic nature. The principles of bone ossification, growth, and remodeling are explored, along with the role of calcium and vitamin D in keeping bones strong and healthy. The various types of bone fractures and their resultant medical corrections to aid in the process of repair and healing are also presented to round out students’ understanding of some common bone disorders.

In the final sections of Chapter 5, the 206 named bones that make up the axial and appendicular skeletons are presented, and their major projections and depressions are identified. A discussion of articulations found in the body follows the bone identification section, and the types of joints (classified both structurally and functionally) are discussed in detail. Joint-related inflammatory disorders are then discussed. The chapter concludes with the differences observed in the fetal skeleton and other developmental events that occur throughout the life span, including osteoporosis.

Suggested Lecture Outline I. 5.1 Bones: An Overview (pp. 130–142) A. 5.1a Functions of the Bones (p. 131) B. 5.1b Classification of Bones (pp. 131–132)

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C. 5.1cStructure of Bone (pp. 132–135) 1. Gross Anatomy of a Long Bone 2. Microscopic Anatomy D. 5.1d Bone Formation, Growth, and Remodeling (pp. 135– 138) 1. Bone Formation and Growth 2. Bone Remodeling E. 5.1e Bone Fractures (pp. 139–142)

II. 5.2 Axial Skeleton (pp. 142–153) A. 5.2a Skull (pp. 142–148) 1. Cranium a. Frontal Bone b. Parietal Bones c. Temporal Bones d. Occipital Bone e. Sphenoid Bone f. Ethmoid Bone 2. Facial Bones a. Maxillae b. Palatine Bones c. Zygomatic Bones d. Lacrimal Bones e. Nasal Bones f. Vomer Bone g. Inferior Nasal Conchae h. Mandible 3. The Hyoid Bone B. 5.2b Vertebral Column (Spine) (pp. 149–151) 1. Cervical Vertebrae 2. Thoracic Vertebrae 3. Lumbar Vertebrae 4. Sacrum 5. Coccyx

DXA Scan (PBSVideo: 3 min, 2014). www.pbs.org/video/healthlink-treatment-andprevention-osteoporosis/ This video can serve as a springboard to discuss osteoporosis.

III. 5.3 Appendicular Skeleton (pp. 153–161) A. 5.3a Bones of the Shoulder Girdle (p. 154) B. 5.3b Bones of the Upper Limbs (pp. 156–157) 1. Arm 2. Forearm INSTRUCTOR GUIDE FOR ESSENTIALS OF HUMAN ANATOMY & PHYSIOLOGY, 13e

Two of the bones in the cranium are often confused by the students: the sphenoid and ethmoid bones. Pass out skulls and show how the sphenoid and ethmoid bones can be identified from different views and have students indicate their locations back to you. By handling the skulls directly, students can understand the threedimensional position of the bones, for example, the lesser wing of the sphenoid forming the posterior medial aspect of the eye socket, as well as the floor of the cranium. For a quick learning tip, relay to the students that the sphenoid bone can be located generally around the eyes, while the ethmoid bone is generally located around the nose. Additionally, displaying an isolated sphenoid bone and ethmoid bone for students to view and touch is helpful.

MEDIA TIP

C. 5.2c Thoracic Cage (pp. 151–153) 1. Sternum 2. Ribs

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3. Hand C. 5.3c Bones of the Pelvic Girdle (pp. 157–159) D. 5.3d Bones of the Lower Limbs (pp. 160–161) 1. Thigh 2. Leg 3. Foot

IV. 5.4 Joints (pp. 163–169) A. 5.4a Fibrous Joints (p. 163) B. 5.4b Cartilaginous Joints (p. 163) C. 5.4c Synovial Joints (pp. 163–165) D. 5.4d Types of Synovial Joints Based on Shape (pp. 165–169)

V. 5.5 Developmental Aspects of the Skeleton (pp. 169–171) A. 5.5a Birth to Adulthood (pp. 169–170) B. 5.5b Older Adults (pp. 170–171) Note: For a list of Key Terms for this chapter, please go to Mastering A&P > Study Area > Additional Study Tools > Key Terms > Chapter 5.

Learning Objectives 5-1

Identify the subdivisions of the skeleton as axial or appendicular.

5-2

List at least three functions of the skeletal system.

5-3

Name the four main classifications of bones.

5-4

Identify the major anatomical areas of a long bone.

5-5

Describe the microscopic structure of compact bone.

5-6

Explain the role of bone salts and the organic matrix in making bone both hard and flexible.

5-7

Describe briefly the process of bone formation in the fetus, and summarize the events of bone remodeling throughout life.

5-8

Name and describe the various types of fractures.

5-9

On a skull or diagram, identify and name the bones of the skull and the four major skull sutures.

5-10 Name the parts of a typical vertebra, and explain in general how the cervical, thoracic, and lumbar vertebrae differ from one another.

5-11 Discuss the importance of the intervertebral discs and spinal curvatures.

5-12 Explain how the abnormal spinal curvatures (scoliosis, lordosis, and kyphosis) differ from one another.

5-13 Name the components of the thoracic cage.

5-14 Describe how a true rib differs from a false rib.

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5-16 Describe important differences between a male and a female pelvis.

5-17 Name the three major structural categories of joints, and compare the amount of movement allowed by each.

5-18 Describe major changes in skeletal development at fetal, infant, youth, and adult stages of life.

5-19 Identify some of the causes of bone and joint problems throughout life.

5-20 Describe how the skull of a newborn infant (or fetus) differs from that of an adult, and explain the function of fontanels.

Resources for Teaching Online Discussion Board Topic: Homeostatic Imbalance—Dislocation In the textbook on page 165, the Homeostatic Imbalance section explains that a dislocation is what happens when a bone is forced out of its proper positioning in the joint cavity. Engage your students by using the following discussion questions in lecture or by posting them to the discussion board on your course management system.

Discussion Questions 1. In which areas of the body do joint dislocations commonly occur?

2. What are the leading causes of dislocations?

3. Reductions are used to treat dislocations. What are the types of reduction treatment?

4. Dislocation and other injuries are on the rise in children and adolescents due to high participation of these populations in competitive sports activities. Some sports organizations are taking proactive action on overuse injuries, such as Little League baseball, with pitchers being restricted to a maximum number of pitches per game or per day. What are your opinions? Use current articles to form your argument.

Potential Student Responses: 1. Shoulder dislocations: glenohumeral dislocations between the humerus and the glenoid cavity of the scapula, as well as acromioclavicular joint dislocations between the clavicle and scapula (separated shoulder). Elbow dislocations and hand/finger dislocations are also very common. Other areas that are commonly dislocated are ankles and hips. A short video about shoulder dislocation can be viewed at emedicine.medscape.com/article/93323-overview.

2. Dislocations are commonly caused in sports injuries (e.g., contact sports such as football, those that involve falls such as gymnastics), vehicle accidents, and falls.

3. Physical examination, X-, CT scans, and possibly MRIs are used to determine the extent of the injury. Occasionally, a dislocation may spontaneously reduce itself (relocation) and the bone can go back into place without assistance. Otherwise the physician will perform a closed reduction during which the bone is manipulated back into place.

Occasionally there is soft tissue (such as tendons and ligaments) around the joint that prevents or blocks closed reduction, and open reduction is required, during which the surgeon operates to put the bone back into its proper position.

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4. There has been an increase in overuse injuries in children and adolescents partially due to the fact that many play sports year-round. Dislocations are only one such injury. Stress fractures, tendonitis, and bursitis are some of the possible injuries, and the growth plate also can be damaged. There can be significant consequences in this population because bone growth is still occurring. Students may debate what the most effective treatments are (e.g., preventative or surgical), as well as what guidelines should be put in place for a particular sport. This may also stimulate discussion with students’ personal experiences in this arena. Current rules for pitching in Little League baseball may also be discussed as an example.

Investigate Online Take learning a step further by searching for relevant research articles on the web. Visit science websites, such as those listed below, and begin by searching for key terms such as joint dislocation, sports injuries, reduction treatment, and child or adolescent overuse injuries, and see how what you’re learning in the course applies to science and medicine today. www.scientificamerican.com www.the-scientist.com www.ncbi.nlm.nih.gov/pubmed www.sciencedaily.com

Study Tips Direct students to the Study Tips feature located in the front of the book.

Mastering A&P Numerous items from Mastering A&P can be demonstrated in class, assigned as homework, or encouraged as study materials. These include practice tests and quizzes, animations and videos, Interactive Physiology (IP), Dynamic Study Modules, Audio Journeys, Practice Anatomy Lab (PAL), PhysioEx, flashcards, glossary, key terms, and more.

Interactive Physiology (IP) The following sections of Interactive Physiology are relevant to this chapter: Skeletal System IP Animation: Bone

Animations and Videos The following animations and videos are relevant to this chapter:

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Bone and Dissection Videos: Bone Videos

Practice Anatomy Lab (PAL)3.1: Including Mobile Flashcards The following sections of PAL3.1 are relevant to this chapter:

Human Cadaver > Axial Skeleton and Appendicular Skeleton and Joints

Anatomical Models > Axial Skeleton and Appendicular Skeleton and Joints

Additional Study Tools The following video is relevant to this chapter:

Focus on Careers > Radiologic Technologist

Lecture Hints 1. Students are fascinated by the differences between male and female skeletons. Have two articulated skeletons, one of each gender, available to point out the differences in such areas as the skull and pelvis, and also discuss the information that skeletons provide in forensic medicine, such as how during an autopsy the hyoid bone can provide evidence as to homicide or suicide.

Key point: There are significant differences not only between the skeletons of males and females but also between athletes and sedentary people, young and old people, and so on, and discussing some of these differences will help students to conceptualize the dynamic nature of bones.

2. Emphasize the dynamic and ready-healing nature of bones and the fact that bones are highly vascular, with this rich blood supply accounting for why “If you are going to break something, break a bone.” Also point out that bony matrix is constantly being produced and reabsorbed for the purpose of calcium balance and to accommodate functional and gravitational stress. Explain that moderate weight-bearing exercise will stimulate bone supercompensation and may delay the development of chronic diseases such as osteoporosis. Discuss the consequences of little or no weight bearing, such as for people who are wheelchair dependent or bedridden.

Key point: The dynamic nature of bones cannot be overemphasized. In this chapter, students learn valuable information about the long-term health of bones and what they 51

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can do to delay or prevent osteoporosis, arthritis, and other homeostatic imbalances.

Appositional growth and bone remodeling can occur throughout the lifespan, even after longitudinal growth ceases.

3. Students are surprised to hear that ossification is incomplete at birth. Remind them of the “soft spots” or fontanels in the infant skull. Share a timetable of ossification with students, and point out that babies crawl and walk at the time that is physiologically right for them, in part based on bone development. Also discuss greenstick fractures and their occurrence in young people whose bones are still developing, and also possible reasons that children recover at a faster rate from a fracture than adults do. Finally, point out that longitudinal growth takes place until the end of adolescence due to the epiphyseal plates; hyaline cartilage areas are ossified later.

Key point: Ossification and bone growth and development are processes that continue into early adulthood.

4. Use a flexible, articulated skeleton to demonstrate the location of bones (including articulating bones) and their markings, as you discuss them in lecture.

Key point: It is important for students to actually see the location of the bones and touch either real bones or plastic models as they hear about each of them individually.

5. Use a skull that has been sectioned transversely to demonstrate the location of the interior bones of the skull as you discuss them during lecture.

Key point: The interior bones of the skull are the most difficult to identify and this helps students to visualize their locations within the skull.

6. Demarcate a skull with a marker to show the various sutures and boundaries between the bones of the skull and discuss the articulations between different bones. There are also color-coded skull models that demarcate major facial and cranial bones to emphasize the location of the bones.

Key point: Some bones of the skull, such as the ethmoid and sphenoid bones, are difficult for students to visualize without using both two- and three-dimensional visual aids. Students sometimes stumble over the medial wall of the orbit where the lacrimal bones are in close proximity to the ethmoid, nasal, and maxillary bones, and the ethmoid bone is adjacent to the sphenoid bone. With visual demarcations, these bones are easier to distinguish.

7. Identify the risk factors for chronic conditions such as osteoporosis and arthritis, and discuss the diagnosis, preventative measures, current treatments, and future therapies for these conditions.

Key point: Osteoporosis and arthritis are major health concerns in our aging population, and this discussion gives students a frame of reference for understanding the causes and treatments for this condition.

8. Identify the placement and functions of the fontanels in fetal and infant skull development. Explain that fontanel means “little fountain” and is related to the fact that a baby’s pulse is palpable at these “soft spots.” This allows the skull to compress slightly during birth and the brain to grow during late pregnancy and early infancy. Go through the developmental time points of closure of these fontanels. Note: The significance of the fontanels is underscored. Examination of fontanels can provide a health indicator because ..

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a depressed fontanel could indicate dehydration while a raised fontanel could indicate increased cranial pressure.

Key point: Students may be familiar with the location of at least the anterior fontanel and may be interested to learn of the others.

9. Spend time discussing the osteon (Haversian system). Students may find this topic confusing, but it is an important concept for them to understand because it directly relates to the dynamic nature of bones, particularly during growth and healing.

Key point: Osteons (Haversian systems), with their interlinked canals and transportation systems, provide living bone cells with the nutrients necessary for growth and healing following overuse or trauma, as well as a means of removing toxic metabolic wastes in order to keep bones healthy.

10. Discuss the various joint disorders that students are familiar with, as well as their causes and treatments. Commonly known disorders are temporomandibular joint (TMJ) disorder, “water on the knee,” bursitis, “tennis elbow,” torn ACLs or menisci, and arthritis (distinguish between rheumatoid and osteoarthritis).

Key point: Joints hold bones together and provide mobility. They are the site of numerous disorders due to overuse and, at times, abuse, and it is valuable for students to appreciate their fragility as well as their complexity.

11. Discuss what it means to be double-jointed.

Key point: This is a familiar condition that students hear about and are interested in exploring. Discuss the misnomer of the condition, the etiology behind hypermobility/hyperlaxity (bone shape, surrounding ligament conditions, etc.), and the possible disease onset consequences of this condition (higher incidences of arthritis at the hypermobile joints, vulnerability to injury at those joints, etc.).

12. Discuss ruptured intervertebral discs and explain the pathology behind this disorder.

Key point: This is often the first time that students have actually seen the vertebral column and the way it is designed to protect the spinal column. Discussing what happens when a disc “leaks” into surrounding tissues helps students to understand the severity of the disorder.

13. Emphasize the differences between osteoclasts (bone-destroying cells) and osteoblasts (bone-forming cells), and explain why a dynamic balance between them is necessary.

Extend the discussion to how such drugs as alendronate work to treat osteoporosis.

Key point: As new bone is formed, which is a constant process, old bone is destroyed.

This represents homeostatic balance using negative feedback loops at their finest.

Bisphosphonates such as alendronate can interfere with osteoclast activity to counteract osteoporosis.

14. Discuss cleft palate and the surgical correction of this condition.

Key point: Even though the maxilla appears to be one bone, it is really two bones fused at the midline. Any disruption in the fusion during fetal life results in a cleft, which severely impedes an infant’s ability to suck in critical nutrition.

15. Explain the root words of the various bones as they are presented (e.g., the manubrium of the sternum means “handle of a sword”; scapula means “spade”). Also discuss how the 53

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true ribs are known as the vertebrosternal ribs, as they articulate with both the vertebrae posteriorly and the sternum anteriorly. The vertebrochondral ribs (false ribs) articulate with the vertebrae posteriorly and the costal cartilage of the seventh rib anteriorly, and the vertebral ribs are the “floating ribs,” because they only articulate with the vertebrae posteriorly, and nothing anteriorly.

Key point: Building upon the students’ vocabulary by providing definitions of word parts helps them to learn the names of all 206 bones more easily and will make muscles easier to locate and describe in Chapter 6.

16. The number of vertebrae within each region of the vertebral column denotes where each region begins and ends. Point out to students that the number of thoracic vertebrae corresponds to the number of ribs. Explain to students that while a normal human has seven cervical vertebrae, he or she will have eight cervical nerves. This is important to remember when the spinal nerves are discussed in Chapter 7.

Key point: Vertebrae are singular, and the spinal nerves are arranged in pairs. Also, the first cervical nerve branches are superior to the first cervical vertebra. Also, draw attention to the relationship between the thoracic vertebrae and rib cage and their articulations.

17. Discuss the impact of bone structure for muscle attachment.

Key point: By understanding the role of bone shape in muscle attachment (and therefore, body movement), students can be better prepared for the muscular system in Chapter 6.

Classroom Demonstrations and Student Activities Classroom Demonstrations 1. Use an articulated skeleton to (a) indicate the protective and supportive aspects of bones, (b) identify individual bones, (c) identify the security aspects of various body joints, and (d) show how bones fit together at joints.

2. Show a video such as the following on how bones are used in forensic science to start a discussion on specific bony landmarks and bones that can help identify characteristics about an individual. ca.pbslearningmedia.org/resource/0fb6c06f-a261-4517-a4a0cf9280a05103/the-bone-lab.

3. Use a femur or humerus cut longitudinally to reveal the inner structures of a long bone.

4. Use a disarticulated skull to demonstrate more clearly the individual skull bones and to show the fragile internal structure of bones containing sinuses (e.g., ethmoid, sphenoid).

Discuss the function of the sinuses and illustrate complementarity of structure and function (e.g., sinuses as resonating chambers, similar to an empty room). Relate these bones in an articulated skull.

5. Use a fetal skeleton to emphasize the changes in skull and body proportions that occur after birth. Point out that initially the skeleton is formed primarily of hyaline cartilage rather than bone and that ossification is the process that replaces the cartilage with bone.

Obtain X-rays of comparative anatomy (i.e., an arm of a child and an arm of an adult) to illustrate the growth plate in the child versus none in the adult. ..

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6. Obtain X-rays of scoliosis patients (posterior view), before, during, and after treatment (with external braces in comparison to internal rods and pins that can be visualized in the X-ray). Discuss the basic scoliosis examination provided by most school nurses.

7. Show a video on the techniques of arthroscopic surgery. Discuss different strategies for ACL reconstruction such as with autografts versus allografts.

8. Obtain X-rays of different fracture types so that students can better visualize these injuries. Use real-world examples to show how different fractures can occur—for example, take a young branch of a tree and create a greenstick fracture and contrast it to bending a brittle branch from the ground.

9. Obtain photographs of open and closed fractures, as well as simple and compound fractures, so that students can better visualize these injuries “from the outside” of the body. Discuss how these injuries can occur.

10. Obtain pictures or models of rods, screws, and joints that are used to fix fractures or worn-out joints. Show them to students. Emphasize structural aspects, such as how the curves of the equipment are complementary to the curvature of the long bones being repaired.

Student Activities 1. Have students put together a disarticulated skeleton (bones are all separate) on a table.

For a more advanced exercise, have students try to figure out left versus right sides of bones, such as the humerus and the femur, and have them explain their choices.

2. Have students look at a full set of disarticulated vertebrae. Ask them to identify which are cervical, thoracic, lumbar, sacral, and coxal. Point out the differences between the groups (such as costal facets for the thoracic vertebrae, or the large size of the body in the lumbar vertebrae) and explain the reasons for those differences.

3. Have students examine the differences between the axis and atlas vertebrae, and relate their structure to their location and function in the vertebral column.

4. Have students get into groups of four or five. Provide a list of bones and major markings and ask the students to manually touch and identify each item on an articulated skeleton (have a skeleton provided for each group). Repeat this exercise over several days and as many times as possible.

5. Using a disarticulated skeleton, hold up various bones and have students try to classify them as long, short, flat, or irregular.

6. Have students try to identify right- and left-side bones using the scapula, humerus, pelvic girdle, and femur. Create an exercise for which students have to discern one left-side bone from a collection of right-side bones, or vice versa. Have students explain their choices.

7. Have students look at microscopic cross sections of compact bone. Ask them to draw and label as many of the parts of the osteon (Haversian system) as they can.

8. Have students create a matching game using pictures of real-world analogies for synovial joints, such as a picture of a door in a door jamb for the uniaxial joint (hinge joint) or a cabinet door and its hinge for the elbow joint (hinge joint).

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9. Have students write down the nutritional components of milk and milk products (they can bring in pictures of the nutrition labels of various products). Discuss why and how dairy products “help build strong bodies.” Have students list other foods that would provide good sources of calcium.

10. Have students research an injury that they or a friend/family member experienced that affected a bone, joint, or associated structure such as a ligament or meniscus. Have students discuss if there have been any changes to diagnostic or treatment techniques since the time the injury occurred.

11. Describe a particular bone location and/or function. Have students then pick up the correct bone from their disarticulated skeleton.

12. Call out various facial and cranial bones and have students point to the appropriate bones on their articulated, unmarked skull.

13. Have students create articulations from a disarticulated skeleton and perform the motions that are possible at the joint to better conceptualize the different synovial joints, such as the plane, pivot, hinge, and so on, and also discuss why the joint is classified as uniaxial, biaxial, or multiaxial.

Media See page 164 for a listing of media distributors.

1. Anatomy of the Ankle and Foot (FHS: 17 min., 1999, VHS, DVD, 3-year streaming webcast). This video examines the major weight-bearing joint, the ankle, along with the bones of the foot and ankle. Common foot and ankle injuries are covered.

2. Anatomy of the Hand (FHS: 14 min., 1999, VHS, DVD, 3-year streaming webcast). This program demonstrates the opposable nature and other functions of the hand.

3. Anatomy of the Knee (FHS: 15 min., 1999, VHS, DVD, 3-year streaming webcast). The intricate nature of the knee joint is examined, as well as some of the most common knee injuries.

4. Anatomy of the Shoulder (FHS: 17 min., 1999, VHS, DVD, 3-year streaming webcast).

This program shows the range of motion that the ball-and-socket joint of the shoulder is capable of and explains the technical specifications involved.

5. Bones and Joints (FHS: 20 min., 1995, VHS, DVD, 3-year streaming webcast). From The New Living Body series, this video introduces the topics of movement, the structure and function of joints, bone growth, and the effects of chronic exercise versus sedentary living on bone health.

6. Treatment and Prevention of Osteoporosis (PBSVideo: 28 min., www.pbs.org/video/health-link-treatment-and-prevention-osteoporosis/). This video discusses osteoporosis and diagnosis, prevention, and treatment strategies.

7. Skeletal System Introduction (Khan Academy: 2016, www.khanacademy.org/science/health-and-medicine/human-anatomy-andphysiology#skeletal-system). Series of tutorial videos on skeletal system microanatomy and anatomy of associated structures. ..

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8. Upper Limb Bone Video for Gross Human Anatomy (MedEdPORTAL Publications, 12 min., 2012 dx.doi.org/10.15766/mep_2374-8265.9217). This short tutorial discusses upper limb structure and the shoulder joint.

9. The Skeletal System: It’s Alive! (Crash Course: 13 min., 2016. www.khanacademy.org/partner-content/crash-course1/partner-topic-crash-course-bioecology/crash-course-biology/v/crash-course-biology-129). This is a short, lively introduction to the structure and function of the skeletal system.

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CHAPTER

6

The Muscular System

Chapter Summary The muscular system presents challenges similar to those in the skeletal system in that this system requires both the conceptualization of complex mechanisms and the memorization of numerous key terms, ranging from microscopic to macroscopic structures. Providing students with a list of criteria used in the naming of muscles helps them overcome their anxiety and helps them view the task as manageable.

This chapter begins with an overview of three types of muscle tissue. Skeletal, smooth, and cardiac muscle characteristics, and the location, function, and level of conscious control of these tissues are compared and contrasted. Because the muscular system refers specifically to only the skeletal muscles, the chapter then focuses on the anatomy and physiology of this tissue type.

The next section of the chapter begins with a discussion of the microscopic anatomy of skeletal muscle, followed by an overview of the mechanism of muscle contraction. The sliding filament theory is initially confusing to students, as it is often difficult for them to visualize this microscopic-level process. It is important to emphasize to the students that the stationary myosin hooks onto and draws in the actin myofilaments, which leads to the shortening of muscle length. However, once the conceptualization of the sliding filament theory is mastered, students are able to understand how muscles respond to various levels of stimulation, the three pathways for generating energy for muscle contraction, and, consequently, how muscle fatigue occurs. The two types of muscle contractions are also discussed; this topic is interesting to students because it helps them review their own exercise regimen.

In the final sections of the chapter, the “Five Golden Rules” of skeletal muscle activity are presented to help students comprehend muscle movements and their related interactions.

First, the types of body movements generated by muscles are explained. Then a basic list of criteria for naming muscles is provided to ensure that students understand the logic involved in the nomenclature. Finally, the most important of the more than 600 muscles of the human body are presented, along with their points of origin and insertion, as well as function.

Suggested Lecture Outline I. 6.1 Overview of Muscle Tissues (pp. 177–181) A. 6.1a Muscle Types (pp. 177–181) 1. Skeletal Muscle 2. Smooth Muscle 3. Cardiac Muscle B. 6.1b Muscle Functions (p. 181) 57

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1. Produce Movement 2. Maintain Posture and Body Position 3. Stabilize Joints 4. Generate Heat 5. Additional Functions

TEACHING TIP While discussing each specific muscle, point out the word parts in its name to emphasize why the muscle was named that way. Remind students that muscles tend to be named from one or more of the following criteria: direction of the fibers, size, location of the muscle or its origin/insertion, number of origins, shape, and action. For example, the sternocleidomastoid originates on the sternum and clavicle (cleido) and inserts on the mastoid process of the temporal bone. The sartorius is named for the Latin sartor, or tailor, and is the muscle used for the cross-legged sitting position once used by tailors.

II. 6.2 Microscopic Anatomy of Skeletal Muscle (pp.

181–183) III. 6.3 Skeletal Muscle Activity (pp. 183–192) A. 6.3a Stimulation and Contraction of Single Skeletal Muscle Fibers (pp. 183–188) 1. The Nerve Stimulus and the Action Potential 2. Mechanism of Muscle Contraction: The Sliding Filament Theory B. 6.3b Contraction of a Skeletal Muscle as a Whole (pp.

188–192) 1. Graded Responses a. Muscle Response to Increasingly Rapid Stimulation b. Muscle Response to Stronger Stimuli 2. Providing Energy for Muscle Contraction 3. Muscle Fatigue and Oxygen Deficit 4. Types of Muscle Contractions—Isotonic and Isometric 5. Muscle Tone 6. Effect of Exercise on Muscles

MEDIA TIP Muscular System at Work: The Inner Athlete (FHS: 24 min., 1998). From The Human Body: Systems at Work series, this program looks at the many roles played by muscle in our everyday lives.

IV. 6.4 Muscle Movements, Roles, and Names (pp. 192– 203) A. 6.4a Types of Body Movements (pp. 192–196) 1. Special Movements B. 6.4b Interactions of Skeletal Muscles in the Body (pp.

196–197) C. 6.4c Naming Skeletal Muscles (p. 198) D. 6.4d Arrangement of Fascicles (pp. 198–199)

V. 6.5 Gross Anatomy of Skeletal Muscles (pp. 199–209) A. 6.5a Head and Neck Muscles (pp. 199–201) 1. Facial Muscles a. Frontalis and Occipitalis b. Orbicularis Oculi c. Orbicularis Oris d. Buccinator e. Zygomaticus ..

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f. Masseter g. Temporalis 2. Neck Muscles a. Platysma b. Sternocleidomastoid B. 6.5b Trunk Muscles (pp. 201–204) 1. Anterior Muscles a. Pectoralis Major b. Intercostal Muscles c. Muscles of the Abdominal Girdle i. Rectus Abdominis ii. External Oblique iii. Internal Oblique iv. Transversus Abdominis 2. Posterior Muscles a. Trapezius b. Latissimus Dorsi c. Erector Spinae d. Quadratus Lumborum e. Deltoid C. 6.5c Muscles of the Upper Limb (p. 204–205) 1. Muscles Causing Movement at the Elbow Joint a. Biceps Brachii b. Brachialis c. Brachioradialis d. Triceps Brachii D. 6.5d Muscles of the Lower Limb (pp. 205–209) 1. Muscles Causing Movement at the Hip Joint a. Gluteus Maximus b. Gluteus Medius c. Iliopsoas d. Adductor Muscles 2. Muscles Causing Movement at the Knee Joint a. Hamstring Group b. Sartorius c. Quadriceps Group 3. Muscles Causing Movement at the Ankle and Foot a. Tibialis Anterior b. Extensor Digitorum Longus c. Fibularis Muscles

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d. Gastrocnemius e. Soleus

VI. 6.6 Developmental Aspects of the Muscular System (pp. 209, 214) Note: For a list of Key Terms for this chapter, please go to Mastering A&P > Study Area > Additional Study Tools > Key Terms > Chapter 6.

Learning Objectives 6-1

Describe similarities and differences in the structure and function of the three types of muscle tissue, and indicate where they are found in the body.

6-2

Define muscular system.

6-3

Define and explain the role of the following: endomysium, perimysium, epimysium, tendon, and aponeurosis.

6-4

Describe the microscopic structure of skeletal muscle, and explain the role of actinand myosin-containing myofilaments.

6-5

Describe how an action potential is initiated in a muscle cell.

6-6

Describe the events of muscle cell contraction.

6-7

Define graded response, tetanus, isotonic and isometric contractions, and muscle tone as these terms apply to a skeletal muscle.

6-8

Describe three pathways for ATP regeneration during muscle activity.

6-9

Define oxygen deficit and muscle fatigue, and list possible causes of muscle fatigue.

6-10 Describe the effects of aerobic and resistance exercise on skeletal muscles and other body organs.

6-11 Define origin, insertion, prime mover, antagonist, synergist, and fixator as they relate to muscles.

6-12 Demonstrate or identify the different types of body movements.

6-13 List seven criteria used in naming muscles.

6-14 Name and locate the major muscles of the human body (on a torso model, muscle chart, or diagram), and state the action of each.

6-15 Explain the importance of a nerve supply and exercise in keeping muscles healthy.

6-16 Describe the changes that occur in aging muscles.

Resources for Teaching Online Discussion Board Topic: Homeostatic Imbalance—Myasthenia Gravis In the textbook on page 214, the Homeostatic Imbalance section discusses myasthenia gravis, an autoimmune disease that exhibits weakened musculature due to the destruction of acetylcholine receptors. Engage your students by using the following discussion questions in lecture or by posting them to the discussion board on your course management system.

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1. Discuss how the lack of acetylcholine receptors affects muscle contraction. Hint: Focus on the events that take place in the neuromuscular junction and the all-or-none law.

2. What is the connection of the thymus gland to this disease?

3. What other diseases have symptoms that are similar to myasthenia gravis? What are their causes?

4. What are the current treatments for myasthenia gravis and how do they work?

Potential Student Responses: 1. Students should discuss that the communication between the motor neuron and the muscle cell is relayed first chemically through the neurotransmitter acetylcholine. Acetylcholine is released into the synaptic cleft; however, with myasthenia gravis there are not enough receptors to bind to on the muscle cell. If there is not a threshold level of acetylcholine bound to its receptors, an action potential event cannot take place. It is an all-ornone phenomenon, where there has to be a critical amount of receptors that are bound to the neurotransmitters to induce the action potential for contraction. In the muscle organ itself, there is a graded response, where some individual muscle cells do reach a critical threshold for contraction, while others do not, thus resulting in weakened or incomplete muscle movement.

2. The thymus gland is responsible during infancy and childhood for programming developing immune cells to recognize self from foreign cells. Normal immune cells ignore selfcells (tolerance). A normal thymus is atrophied in adults, but in myasthenia gravis patients, the thymus is large and still active. It is thought that there is a dysfunction in the thymus, where there is a breakdown in tolerance, and thus the immune cells mistake the acetylcholine receptors as foreign and attack them.

3. Lambert-Eaton myasthenic syndrome (LEMS) can have symptoms that are similar to myasthenia gravis (MG). LEMS, however, is caused by autoimmune damage to the nerve, rather than the muscle. Electromyograph (EMG) and blood tests can be used to discern which disease the patient has. Multiple sclerosis (MS) may also be confused with MG. MS is thought to be an autoimmune disease that affects the myelination of axons in the brain and spinal cord.

4. Drugs that inhibit the breakdown of acetylcholine, such as neostigmine and pyrostigmine, often are prescribed. Other treatments include administration of immunosuppressants such as corticosteroids (prednisone) or medications such as azathioprine, mycophenolate mofetil, cyclosporine, methotrexate, or tacrolimus; plasmapheresis, where blood plasma containing the autoantibodies is removed and replaced with comparable fluids; intravenous immunoglobulin treatment; monoclonal antibody infusion treatment; or even thymectomy, where the thymus is removed.

Investigate Online Take learning a step further by searching for relevant research articles on the web. Visit science websites, such as those listed below, and begin by searching for key terms such as myasthenia gravis treatment, myasthenia gravis review, myasthenia gravis and thymus, congenital myasthenia, and acquired myasthenia and see how what you’re learning in the course applies to science and medicine today.

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www.sciencedaily.com www.scientificamerican.com www.the-scientist.com www.ncbi.nlm.nih.gov/pubmed www.myasthenia.org

Study Tips Direct students to the Study Tips feature located in the front of the book.

Mastering A&P Numerous items from Mastering A&P can be demonstrated in class, assigned as homework, or encouraged as study materials. These include practice tests and quizzes, animations and videos, Interactive Physiology (IP), Dynamic Study Modules, Audio Journeys, Practice Anatomy Lab (PAL), PhysioEx, flashcards, glossary, key terms, and more.

Interactive Physiology (IP) The following sections of Interactive Physiology are relevant to this chapter: Muscular System IP2: The Neuromuscular Junction IP2: Excitation–Contraction Coupling IP2: Cross-Bridge Cycling IP Animation: Cross-Bridge Cycle IP Animation: Events at the Neuromuscular Junction IP Animation: Muscle Metabolism

PhysioEx10.0 The following sections of PhysioEx10.0 are relevant to this chapter:

Videos of PhysioEx Lab Experiments: Skeletal Muscle

Exercise 2: Skeletal Muscle Physiology

Animations and Videos

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The following animations and videos are relevant to this chapter:

A&P Flix: A&P 3D Animations > Events at the Neuromuscular Junction; Excitation–Contraction Coupling; The Cross-Bridge Cycle

A&P Flix: Origins, Insertions, Actions, Innervations > Head and Neck; Trunk; Upper Limb; Lower Limb

A&P Flix: Group Muscle Actions and Joints > Unit 1: Muscles that act on the shoulder joint and humerus; Unit 2: Muscles that act on the elbow joint and forearm; Unit 3: Muscles that act on the wrist and finger; Unit 4: Muscles that act on the hip joint and femur; Unit 5: Muscles that act on the knee joint and lower leg; Unit 6: Muscles that act on the ankle joint

Bone and Dissection Videos > Cat Dissection > Superficial Muscles of the Trunk; Deep Muscles of the Trunk; Posterior Muscles of the Hip and Thigh

Bone and Dissection Videos > Fetal Pig Dissection > Muscles of the Forelimb; Muscles of the Hindlimb; Muscles of the Head, Neck, and Trunk

Practice Anatomy Lab (PAL)3.1: Including Mobile Flashcards The following sections of PAL3.1 are relevant to this chapter:

Human Cadaver > Muscular System > Head and Neck; Trunk; Upper Limb; Lower Limb

Anatomical Models > Muscular System > Head and Neck; Trunk; Upper Limb; Lower Limb

Histology > Muscular System

Cat > Muscular System

Fetal Pig > Muscular System

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Additional Study Tools The following video is relevant to this chapter:

Focus on Careers > Massage Therapist

Lecture Hints 1. Emphasize the increasing levels of organization that lead to a complete muscle. Discuss how actin and myosin myofilaments make up the sarcomere, which is a contractile unit of a myofibril. The myofibrils in turn are grouped together to form the muscle fiber or cell. The muscle fibers/cells are wrapped in a protective sheath, the endomysium. At the next level, describe the fascicle, which is composed of several sheathed muscle fibers wrapped in their own protective covering, the perimysium. And, finally, point out that bundles of fascicles are wrapped by another protective covering, the epimysium, to form the complete muscle organ.

Key point: This hierarchy of organization follows the concepts we have been discussing since Chapter 1 and helps students understand the consistency of the pattern.

2. Use slides and microscopes to have students look at each of the muscle types (cardiac, smooth, and skeletal) while discussing their similarities and differences.

Key point: It is important for students to understand that each muscle type has a structure relevant to its function—for example, cardiac muscle is different from the other two types because of its specific role as a continuously contracting circulatory pump. It is important and more relevant to the students to see actual micrographs or slides under the microscope of the three muscle tissue types, rather than stylized drawings.

3. Students often struggle with grasping the sliding filament theory. Be prepared to spend extra time on this concept. First discuss the new terminology relevant to the process, and then apply that terminology to the way the mechanism works. One analogy is of a rowboat moving through water, with the oars (myosin heads) pulling the boat (actin) along with each stroke, to help clarify the concept. Students may also understand the concept of the myosin, essentially “ratcheting” or acting similar to a catapult being cocked and pulling the actin inward to result in muscle fiber shortening and, therefore, contraction in the muscle organ. Note that Huxley’s sliding filament theory is unique in that other scientists have not improved his explanation of muscle contraction even after seven decades of research.

Key point: This topic is often one of the most difficult concepts in the muscular system for students to initially understand; however, when this concept is understood, the students happily realize how the mechanism of contraction is intuitively straightforward.

Visual aids are very important to help students conceptualize the mechanism.

4. Discuss the importance of calcium in the process of muscle fiber contraction.

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Key point: Students may not realize that calcium plays an important role in both the motor neuron and the muscle fiber. Extracellular calcium entering into the axon terminal signals acetylcholine release, and intracellular calcium will allow myosin binding sites on actin to be exposed to allow for sliding of the actin toward the center of the sarcomere.

5. Another difficult concept for students to grasp is the action between a neuron and all the skeletal muscle cells it stimulates. Discuss a motor unit and the activity at the neuromuscular junction. Be sure that students understand the interplay between the nervous system and the muscular system, which results in muscle activity.

Key point: Clarifying this interplay now will help greatly as students begin to study the nervous system in greater detail in the following chapter. Note that a skeletal muscle cannot contract unless it is stimulated by a motor nerve, as there must be communication from the brain. Emphasize the relationship between the number of muscle fibers innervated by one motor nerve and the amount of motor control exhibited (gross versus fine motor control).

6. Explain that the “all-or-none” law of muscle physiology can be likened to a light switch.

It is either on or off—nothing in between. Point out that this law applies to an individual muscle cell and not the whole muscle, thus providing a muscle with the ability to generate a graded response.

Key point: This is often difficult for students to visualize until it is explained that a muscle is made up of thousands of muscle cells, and if only a few of those cells contract to their full capacity, the overall response is still going to be minimal, such as a twitch. In contrast, if many cells contract, objects can be moved or locomotion can result.

7. Discuss disorders of the neuromuscular junction, such as the effects of botulism and snake venom. Discuss the use of botulinum toxin in Botox injections for both cosmetic and therapeutic reasons. Explain why this toxin can be injected but not ingested.

Key point: These are real-world examples that help consolidate the concepts of synaptic imbalance for the students. Many students are familiar with the Botox procedure and enjoy learning the science behind it. Some students may only be aware of the administration for cosmetic purposes, but not how it can be used to treat such disorders as strabismus, hypochondriasis, migraines, and cerebral palsy–related uncontrolled movements.

8. Students enjoy learning about muscle fatigue and oxygen debt. Nearly everyone has experienced the short-lived muscle fatigue that follows a new exercise routine, and this presents a good opportunity to explain the mechanism involved. Students appreciate learning that the soreness will last until the oxygen debt has been “paid back” and the accumulated lactic acid has been converted into ATP and creatine phosphate reserves. Note that delayed muscle soreness after prolonged endurance events, such as a marathon, is not due to lactic acid accumulation, as blood lactate levels return to normal a few minutes after finishing the race.

Key point: This is a great opportunity for students to apply some of their newly gained knowledge to an everyday occurrence and learn why, for example, you should be able to maintain a pace of exercise that makes it possible to burn calories but still allows you to talk, instead of panting for breath.

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9. Provide students with several examples of the muscle movement of prime movers and their opposing movements by antagonists. Also discuss the role of synergists and fixators in each of the movements.

Key point: This helps students see that for every muscle action there is a counterbalancing reaction. It also clarifies the point that muscles can only contract and that the opposing action requires contraction of another antagonist muscle. Diseases of the neuromuscular system become evident when an agonist muscle is not appropriately balanced by its antagonist.

10. Demonstrate in class the various body movements as they are discussed in lecture. Do this in conjunction with displaying Figures 6.13 and 6.14 so that students can understand and remember the actions illustrated in the textbook. Extend this topic by discussing the location of the muscles that are necessary for each movement (as per Figure 6.14).

Key point: It is helpful for students to observe the actions taking place as they are being discussed, rather than trying to visualize them from the text. Students find the demonstrations entertaining, and the actions and the locations of the muscles that cause them tend to be retained in their memory.

11. Point out to students that although there are more than 600 muscles in the human body, they will only be asked to memorize a select group. Provide them with a list of the muscles that they are responsible for memorizing. Link this to the above lecture hint so that there is a paired association with the muscle names, locations, and functions. This objective can be increased in complexity if origin and insertions are added for study; however, at this course level it may be adequate to focus on muscle identification, location, and action.

Key point: A one-semester course is simply not long enough for students to learn all of the muscles of the human body. For students choosing to go into a field such as medicine, an upper-level anatomy and physiology course series will be part of their future curriculum. Nevertheless, this course will provide them with a good foundation for the major muscles in the body.

12. Discuss disorders of the muscular system such as muscular dystrophy, fibromyalgia, and myasthenia gravis. Compare similarities of the diseases, as well as the differences, such as the causes.

Key point: Students have usually heard about these conditions and appreciate learning about their underlying pathology. Discussing the similarities and differences of disease etiologies and symptoms will help students better understand normal functioning of the cells involved.

13. Have a physical therapist, occupational therapist, or a physical medicine and rehabilitation (PM&R) physician speak to the class about muscle rehabilitation after surgery, an illness, an injury, or a disease condition.

Key point: Students can learn the practical application of muscle movements in the medical field.

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Classroom Demonstrations 1. Demonstrate that muscles move only through contraction. Use the biceps brachii and triceps brachii to illustrate the antagonistic movements, depending on which muscle is contracting. Have students put their hand on their own arm muscle when flexing and extending or have them flex and extend in front of a mirror.

2. Use models and micrographs to compare the three types of muscle tissue and point out the unique structural characteristics of each. If possible, project the field of view from a microscope on-screen, while giving them an introduction to operating the microscope.

3. Use a model to demonstrate the sliding filament mechanism, or make your own model out of disk-shaped Styrofoam pieces placed on pickup sticks to represent Z lines on myofilaments. A general conceptual model is also appropriate where two students each hold a piece of paper horizontally next to each other, and then the instructors pierce the pieces of paper with a pencil or paper clip at a perpendicular angle (vertical) and draw the pieces inward, closer together.

4. Show a model of the neuromuscular junction to help students conceptualize the interplay between the muscular and nervous systems.

5. Demonstrate the difference between isotonic and isometric exercises, and discuss the ways isometric, or resistance, exercises differ from aerobic, or endurance, types of exercise. In addition, discuss which forms of exercise have both isotonic and isometric components and demonstrate examples of these types of exercises.

6. Demonstrate muscle contraction (twitch contractions, summation, and tetanus) using a simple myograph or kymograph apparatus and the gastrocnemius muscle of a frog.

7. Show a video of an electromyograph (EMG) procedure, and discuss how assessment of damage to nerve versus muscle tissue can be determined.

8. Show a photograph of a piece of steak. Explain how the steak is skeletal muscle and the “grain” of the meat is fascicles. Fascia, or the “gristle,” and tendons may also be located and visualized.

Student Activities 1. Divide the class into small groups. Have students demonstrate to each other the differences between various types of body movements, such as flexion, extension, abduction, and adduction. Be sure that they try these movements with different groups of muscles, including muscles of the hands, arms, and legs.

2. Call out an action, and ask students to provide the name of the muscle or muscles responsible for that action. Students can also be challenged to identify the antagonists and synergists when given the name of a muscle. This can be made into a game, with the use of a spinner to point to different muscles or movements to be done, or using cards with the muscle or action written on one side.

3. Have students work in pairs as follows: One student attempts to contract a particular muscle, while the partner provides resistance to prevent that movement. In this way, the muscle will produce its maximal “bulge.” Each student should palpate muscles in both the relaxed and contracted states. For example, the demonstrator can attempt to extend

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his or her knee while the person providing the resistance holds the lower leg to prevent its movement. The quadriceps on the anterior thigh will bulge and be easily palpated.

4. Have students obtain information on the procedures used to build muscle mass and how those procedures accomplish that goal. Also discuss atrophy as a result of wearing a cast on a broken limb or from prolonged hospitalization with minimal activity and discuss what can be done about it, and how this differs from atrophy resulting from paralysis.

This is also a good segue to link the skeletal and muscular systems and discuss why weight-bearing exercise is important to stimulate not only osteoblast activity in bone but also the reinforcement of joints with the increase in mass of the surrounding skeletal muscle.

5. Have students examine an EMG printout of a normal and damaged muscle. Have them determine if the abnormality of the damaged muscle lies in activity level, timing of response to stimulation, and/or quickness to fatigue.

6. Provide articulated skeletons to students in small groups. Ask the students to point out the origins and insertions of various muscles, as well as the movement that each muscle generates.

7. Call out muscle names and have students point to the appropriate muscle on a torso model, as well as to the area on their own body. Muscle actions can also be called out as in #2, and students can point to the appropriate muscle on the torso model.

8. Have students discuss human bipedalism and connect concepts from the chapter to an article from PBS’s Nova series entitled “Our Improbable Ability to Walk,” which can be found online at www.pbs.org/wgbh/nova/body/our-ability-to-walk.html

Media See page 164 for a listing of media distributors.

1. Muscle and Bone (AMB: 30 min., 2002, VHS, DVD). From the Body Atlas series, this video looks at the interrelationship of muscle and bone in movement.

2. Muscular System Introduction (Khan Academy, 2016, www.khanacademy.org/science/health-and-medicine/human-anatomy-andphysiology#introduction-to-muscles). Series of tutorial videos on the muscular system, including discussions on muscle contraction, the role of calcium, the three muscle tissue types, and regulation by the nervous system. Self-quizzes are also included at the end of the study unit.

3. Big Guns: The Muscular System (Crash Course: 13 min., ca.pbslearningmedia.org/resource/591a021a-82c8-4864-ad6a-69b7f0f7cdda/big-gunsthe-muscular-system-crash-course-biology-31). An entertaining yet detailed introduction to the microanatomy of a muscle cell and the process of muscle cell contraction.

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CHAPTER

7

The Nervous System

Chapter Summary The nervous system is the body’s fast-acting master control center. It monitors changes inside and outside the body, integrates sensory input, and quickly generates an appropriate feedback response. Working together with the slower-acting endocrine system, which is the body’s second most important regulating system, the nervous system is able to constantly regulate and maintain homeostasis within narrow limits that are necessary for proper physiological functioning. This chapter looks at both the structural and functional classifications of the nervous system, first separately and then as an integrated whole, to help students conceptualize the complexity of this system.

This chapter begins by describing the structure and function of nervous tissue. The types and activities of the supporting cells, or neuroglia, are discussed, followed by a complete description of the anatomy of a neuron. Neurons are then functionally classified as either sensory (afferent) neurons, bringing stimuli information to the central nervous system; interneurons (association neurons) that integrate the information and create instructions to deal with stimuli; or motor (efferent) neurons that transport the instructions from the central nervous system to the effector organ or gland. Neurons are then structurally classified based on the number of processes emerging from the cell body. Discussion of the physiology of nerve impulses is next, focusing on the two functional properties of neurons, irritability and conductivity. Both of these properties are explored, and the mechanisms involved within simple and more complex reflex arcs are explained to help clarify application of these principles.

The next section of the chapter presents the central nervous system and its components.

The structure and function of the cerebral hemispheres, diencephalon, brain stem, cerebellum, and spinal cord are explored, followed by a discussion of the protection provided to the CNS by the meninges and cerebrospinal fluid. A discussion of some of the more common brain dysfunctions showcases their variability and provides interesting starting points for classroom discussions.

The final section of this chapter examines the peripheral nervous system, beginning with the cranial and spinal nerves, followed by a discussion of the differences between the somatic and autonomic nervous systems. The autonomic nervous system is then further subdivided into its sympathetic and parasympathetic divisions, and the “fight or flight” functions of the sympathetic division are contrasted with the “rest and digest” roles of the parasympathetic division. Finally, the developmental aspects of the nervous system are presented, along with a discussion of some of the more common congenital complications, such as cerebral palsy and spina bifida.

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Suggested Lecture Outline I. 7.1 Organization of the Nervous System (pp. 221–222) A. 7.1a Structural Classification (p. 222) B. 7.1b Functional Classification (p. 222)

II. 7.2 Nervous Tissue: Structure and Function (pp. 222–234) A. 7.2a Supporting Cells (pp. 222–224) B. 7.2b Neurons (pp. 224–229) 1. Anatomy a. Cell Body b. Processes c. Myelin Sheaths d. Terminology 2. Classification a. Functional Classification b. Structural Classification C. 7.2c Physiology: Nerve Impulses (pp. 229–232) a. Electrical Conditions of a Resting Neuron’s Membrane b. Action Potential Initiation and Generation c. Transmission of the Signal at Synapses D. 7.2d Physiology: Reflexes (pp. 232–234.

TEACHING TIP Emphasize to students how nerve transmission from neuron to neuron is very similar to how motor neurons communicate to their respective muscle cells.

Before going into detail on the mechanism of nerve transmission, have students describe how the motor neuron stimulates contraction in the muscle cell. Have students hypothesize how nerve cells communicate to one another, and the effects of having multiple synapses of one neuron to many other neurons.

III. 7.3 Central Nervous System (pp. 234–251) A. 7.3a Functional Anatomy of the Brain (pp. 234–242) 1. Cerebral Hemispheres a. Cerebral Cortex b. Cerebral White Matter c. Basal Nuclei 2. Diencephalon 3. Brain Stem a. Midbrain b. Pons c. Medulla Oblongata d. Reticular Formation 4. Cerebellum

MEDIA TIP The Nervous System (Crash Course: 13 min., 2012, Web education, www.ca.pbslearningmedia.o rg/resource/aa1cd7a3-d83c471c-8b9b246c1221b95d/the-nervoussystem-crash-coursebiology-26). A brief overview of the structures that make up the nervous system and their functions.

B. 7.3b Protection of the Central Nervous System (pp. 242– 246) 1. Meninges 2. Cerebrospinal Fluid 3. The Blood–Brain Barrier C. 7.3c Brain Dysfunctions (pp. 246–248) 71

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1. Traumatic Brain Injuries 2. Cerebrovascular Accidents D. 7.3d Spinal Cord (pp. 248–251) 1. Gray Matter of the Spinal Cord and Spinal Roots 2. White Matter of the Spinal Cord

IV. 7.4 Peripheral Nervous System (pp. 251–263) A. 7.4a Structure of a Nerve (pp. 251–252) B. 7.4b Cranial Nerves (pp. 252–255) C. 7.4c Spinal Nerves and Nerve Plexuses (pp. 252, 256–258) D. 7.4d Autonomic Nervous System (pp. 252, 259–263) 1. Somatic and Autonomic Nervous Systems Compared 2. Anatomy of the Parasympathetic Division 3. Anatomy of the Sympathetic Division 4. Autonomic Functioning a. Sympathetic Division b. Parasympathetic Division

V. 7.5 Developmental Aspects of the Nervous System (pp. 263–267) Note: For a list of Key Terms for this chapter go to Mastering A&P > Study Area > Additional Study Tools > Key Terms > Chapter 7.

Learning Objectives 7-1

List the general functions of the nervous system.

7-2

Explain the structural and functional classifications of the nervous system.

7-3

Define central nervous system and peripheral nervous system, and list the major parts of each.

7-4

Describe the structures and functions of neurons and neuroglia.

7-5

Describe the general structure of a neuron, and name its important anatomical regions.

7-6

Describe the composition of gray matter and white matter.

7-7

Classify neurons according to structure and function.

7-8

List the types of general sensory receptors and describe their functions.

7-9

Describe the events that lead to the generation of a nerve impulse and its conduction from one neuron to another.

7-10 Define reflex arc, and list its elements.

7-11 Identify and indicate the functions of the major regions of the cerebral hemispheres, diencephalon, brain stem, and cerebellum on a human brain model or diagram.

7-12 Name the three meningeal layers, and state their functions.

7-13 Discuss the formation and function of cerebrospinal fluid and the blood–brain barrier.

7-14 Compare the signs of a CVA with those of Alzheimer’s disease; of a contusion with those of a concussion.

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7-16 List two important functions of the spinal cord.

7-17 Describe spinal cord structure.

7-18 Describe the general structure of a nerve.

7-19 Identify the cranial nerves by number and by name, and list the major functions of each.

7-20 Describe the origin and fiber composition of (1) ventral and dorsal roots, (2) the spinal nerve proper, and (3) ventral and dorsal rami.

7-21 Name the four major nerve plexuses, give the major nerves of each, and describe their distribution.

7-22 Identify the site of origin, and explain the function of the sympathetic and parasympathetic divisions of the autonomic nervous system.

7-23 Contrast the effect of the parasympathetic and sympathetic divisions on the following organs: heart, lungs, digestive system, blood vessels.

7-24 List several factors that may have harmful effects on brain development.

7-25 Briefly describe the cause, signs, and consequences of the following congenital disorders: spina bifida, anencephaly, and cerebral palsy.

7-26 Explain the decline in brain size and weight that occurs with age.

7-27 Define senility, and list some possible causes

Resources for Teaching Online Discussion Board Topic: Homeostatic Imbalance—Meningitis In the textbook on page 242, the Homeostatic Imbalance section explains that meningitis, caused by either viruses or bacteria, is an inflammation of the meninges, which cover the brain and spinal cord. Engage your students by using the following discussion questions in lecture or by posting them to the discussion board on your course management system.

Discussion Questions 1. How is meningitis contracted? What is the difference between viral and bacterial meningitis?

2. How are viral and bacterial meningitis treated?

3. How does meningitis cause hearing loss?

4. In 2013, there was an unusual outbreak of fungal meningitis in some patients who were administered epidural prednisone (corticosteroids). Meningitis due to fungal infection is rarely observed. What were the symptoms? What was the cause? What is the treatment?

Potential Student Responses: 1. Viral meningitis is more commonly contracted than bacterial meningitis but tends to be less severe. Viral meningitis tends to be spread from contact with stool/feces, as the viruses that cause the disease are enteric (intestinal) viruses. Viral meningitis causes the following symptoms: a severe headache, fever, nausea or vomiting, irritability, stiff neck, rash, or fatigue. This meningitis lasts about 7–10 days. Bacterial meningitis is more severe, and there is potential for permanent damage in the brain and/or hearing abilities, or 73

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even death. Symptoms are similar to those of viral meningitis, where there is a severe headache, a stiff neck, and a high fever, with nausea, vomiting, or sensitivity to bright lights. Bacterial meningitis can be spread through respiratory and throat secretions, but it is less contagious than a cold.

2. Culturing and testing the spinal fluid from potential patients can help discern whether the meningitis is viral or bacterial in nature. If viral, there is no treatment, and because the disease is mild, it will resolve on its own. If bacterial, antibiotics are administered and are effective if the meningitis is still in the early stages.

3. The infection can spread to the inner ear, where the cochlea is damaged (cochlear ossification), and/or the auditory nerve itself can be damaged by the inflammation in the meninges through inflammation-induced hypoxia in the brain, or through increased intracranial pressure on the nerve.

4. Fungal meningitis has symptoms similar to bacterial and viral meningitis. Most recently, an outbreak occurred in patients given inadequately sterilized (and therefore fungal contaminated) prednisone through epidural injection. A single compounding pharmacy was found to be the source of the contaminated prednisone. The symptoms tended to be relatively mild: headache, fever, sensitivity to light, stiff neck, weakness and numbness, slurred speech and increased pain, redness, or swelling at the injection site. Diagnosis of fungal infection is done through blood or cerebrospinal fluid sampling, and treatment is IV-administered high-dose antifungal medication.

Investigate Online Take learning a step further by searching for relevant research articles on the web. Visit science websites, such as those listed below, and begin by searching for key terms such as meningitis, bacterial meningitis, viral meningitis, fungal meningitis outbreak, meningitis epidemiology, and meningitis treatment and see how what you’re learning in the course applies to science and medicine today. www.sciencedaily.com/ www.scientificamerican.com/ www.the-scientist.com/ www.ncbi.nlm.nih.gov/pubmed/

Study Tips Direct students to the Study Tips feature located in the front of the book.

Mastering A&P Numerous items from Mastering A&P can be demonstrated in class, assigned as homework, or encouraged as study materials. These include practice tests and quizzes, animations and videos, Interactive Physiology (IP), Dynamic Study Modules, Audio Journeys, Practice Anatomy Lab (PAL), PhysioEx, flashcards, glossary, key terms, and more.

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Interactive Physiology (IP) The following sections of Interactive Physiology are relevant to this chapter: Nervous System I—The Neuron: The Action Potential IP Anatomy Review Animation: Nervous I IP2: Resting Membrane Potential IP2: Generation of an Action Potential IP Animation: Resting Membrane Potential IP Animation: Generation of the Action Potential IP Animation: Propagation and Velocity of the Action Potential Nervous System II—The Neuron: Synaptic Potentials and Neurotransmitters IP Animation: Events at the Synapse

PhysioEx10.0 The following sections of PhysioEx10.0 are relevant to this chapter:

Videos of PhysioEx Lab Experiments: Nerve Impulses

Exercise 3: Neurophysiology of Nerve Impulses

Animations and Videos The following animations and videos are relevant to this chapter:

A&P Flix: Resting Membrane Potential; Generation of an Action Potential; Propagation of an Action Potential

BIO Flix: How Synapses Work

Bone and Dissection Videos > Cow and Sheep Dissection > Sheep brain: brain stem, Sheep brain: dorsal surface, Sheep brain: frontal section, Sheep brain: midsagittal section, Sheep brain: ventral surface, Sheep brain: ventricles, Sheep brain: diencephalon

Bone and Dissection Videos > Cat Dissection > The brachial plexus 75

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Bone and Dissection Videos > Fetal Pig Dissection > Spinal cord and spinal nerves

Practice Anatomy Lab (PAL)3.1: Including Mobile Flashcards The following sections of PAL3.1 are relevant to this chapter:

Anatomical Models > Nervous System > Central Nervous System, Peripheral Nervous System, Autonomic Nervous System

Histology > Nervous Tissue

Human Cadaver > Nervous System > Central Nervous System, Peripheral Nervous System, Autonomic Nervous System

Cat > Nervous System

Lecture Hints 1. Before going into depth, outline the general organization of the nervous system on the board, comparing the central nervous system (the brain and spinal cord) to the peripheral nervous system (the cranial and spinal nerves). Further outline the two divisions of the peripheral nervous system—the sensory and motor divisions—followed by the two subdivisions of the motor division—the somatic (voluntary) and autonomic (involuntary) nervous systems. Give a brief description and a specific example of the distinct role of each division. For example, discuss the reflex response that occurs when a ball is thrown at you: Do you duck or catch it? Ask students what divisions are responsible for sensing the ball, processing the ball coming at you, and deciding about how to respond. How do you throw the ball back?

Key point: Point out that any attempt to divide the nervous system into discrete sections is done strictly to help us understand the workings of this complex system, and allow students to associate the divisions. Emphasize that the divisions are made for simplification purposes only.

2. Discuss the neuroglia as the “glue that holds the nervous system together.” These supporting cells are frequently ignored in favor of the “star” (i.e., the functional neuron), and it is wise to emphasize their importance early. Discuss specifically how these cells play an important role: Briefly go over the blood–brain barrier and how glial cells play a role, myelination, and so on, as well as other more recent discoveries such as the role that astrocytes play in learning and memory, even though they are not neurons. Also discuss how there are tenfold more neuroglia than neurons.

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Key point: Although the functional unit of the nervous system is the neuron, the neuroglia provide them with support, protection, access to nutrients, and numerous other lifesustaining services, including enhancement of neuronal function.

3. Discuss why damage in the peripheral nervous system may be overcome, while damage in the central nervous system is not likely to be repaired.

Key point: In the PNS, Schwann cells can secrete chemicals that enhance axonal repair, while oligodendrocytes, located in the CNS, do not. In addition, oligodendrocytes secrete inhibitory molecules that prevent axonal regeneration.

4. First introduce the neuron with either images from the Instructor’s Resource DVD/website or a three-dimensional model to present the basic anatomy of a typical multipolar neuron. Point out to students that neurons come in a variety of shapes and sizes and that they are looking at a representative sample to help visualize commonalities.

Show micrographs of actual unipolar, bipolar, and multipolar neurons for emphasis.

Key point: It is important for students to first understand the general structure of a neuron before they learn of the many variations that are possible. You might also discuss location and function of the different neuronal types, time permitting.

5. To help students understand the importance of the myelin sheath, discuss multiple sclerosis and its effects. Point out that the types of abilities that are lost are dependent upon the position of the sclerotic patches within the nervous system, which accounts for the wide range of disability seen in people with multiple sclerosis.

Key point: Multiple sclerosis causes the conversion of the myelin sheath into sclerotic, or hard, patches that short-circuit the neurological transmissions that would normally pass through that point.

6. Describe saltatory conduction, in which a nerve impulse leaps from node to node, much like skipping down the street. Saltatory conduction is significantly faster than continuous conduction, and nerve impulses traveling on myelinated fibers are faster than those traveling on unmyelinated fibers.

Key point: This visualization helps students understand the differences in the speed of transmission between gray matter and white matter.

7. Differentiate between sensory (afferent) neurons, motor (efferent) neurons, and interneurons (association neurons), and describe the role of each. Point out that nerves, which are bundles of neuron fibers, can carry sensory, motor, or both types of fibers at the same time, similar to a telephone wire that transmits messages both ways.

Key point: Describe the direction in which the messages run in relation to the CNS. 8. Distribute handouts of “brain maps” that show the most current, detailed outlines of the activities attributed to various parts of the brain. Discuss the Human Connectome Project and its success at mapping new areas of the brain. Discuss epilepsy and how this disorder contributed to brain mapping. Also include past and present treatment strategies for epilepsy. Discuss the different types of seizures associated with epilepsy.

Key point: Students are fascinated to learn how much we have discovered through studying people with seizure disorders and other neurological conditions, as well as through modern brain mapping techniques.

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9. Discuss the effects of a stroke, or cerebrovascular accident, if the cranial bleed is located in Broca’s area. Further elaborate on the other types of aphasia and their causes. Ask the students to predict the results of a bleed in either the gustatory or olfactory area.

Key point: Students usually know that some people become aphasic following a stroke and others do not. This discussion helps them understand the processes and consequences involved.

10. Have students watch a video of a person undergoing brain surgery while retaining consciousness, such as this video from National Geographic (3:14): www.video.nationalgeographic.com/video/00000144-0a23-d3cb-a96c-7b2ffbdb0000 Key point: Students will be amazed that a person can stay conscious during the surgery (although the patient is sedated during the opening of the skull due to pain receptors in the scalp); this underscores the fact that there are no pain receptors on the surface of the brain itself.

11. Ask the students if they can guess whether they are predominantly left- or right-brained, and then list some of the characteristics associated with dominance of each on the board.

Key point: “Artistic” or “analytic” are some of the adjectives frequently used to describe brain dominance. Explain that we all have the ability to use both sides of our brain, but we typically display more characteristics of dominance by one side than by the other.

Note that a cerebrovascular accident (CVA) on the left side of the brain will affect the limbs on the right side of the body (and vice versa). Explain the concept of contralateral control—how the left side of the brain can compensate and “learn” some of the activities that were originally associated with the right side (and vice versa) after a brain injury or CVA. It is also important to explain how some brain functions may be permanently destroyed.

12. Emphasize that the hypothalamus is one of the key regulators of homeostasis and that it is particularly important in temperature control, water balance, metabolism, and hormone regulation. Also, because the hypothalamus is part of the limbic system, when people are frightened, they can get goose bumps, much like when they are cold. Also note that the medulla oblongata is important in maintaining homeostasis in that it regulates the vital activities of heart rate, blood pressure, and breathing. The pons is also involved in the regulation of breathing.

Key point: Different areas of the brain work together and coordinate complementary functions to maintain homeostasis.

13. Describe the differences between Alzheimer’s disease, Parkinson’s disease, and Huntington’s disease, and explain the reasons for their differences.

Key point: These three conditions are well-known and generate a lot of discussion in the classroom. Explain current research and treatment options.

14. Describe and discuss brain conditions that require psychiatric treatment, such as depression, bipolar disorder, schizophrenia, multiple personality disorder, sociopathic behavior, or psychosis, and their relationship with specific neurotransmitter dysregulation.

Key point: By gaining knowledge of these conditions, students can better appreciate the complexity and individual variation within the nervous system.

15. Discuss the effect of stress on the immune system and introduce the field of psychoneuroimmunology. Talk with students about how test anxiety and stress during finals (acute, ..

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short-term stress) can affect their immunity; long-term caregiver stress for such diseases as Alzheimer’s disease can lead to subsequent incidences of depression that are associated with increased disease susceptibility. Discuss intervention strategies to lower risk of disease onset in these individuals with chronic stress.

Key point: Stress that is perceived and integrated by the brain has implications for homeostatic imbalance, as the hypothalamus can directly impact the endocrine system, which in turn can suppress the immune system. Studies have shown that social support in long-term stress can be beneficial. These are concepts that students find relevant and can aid in understanding how various organ systems work together to maintain homeostasis in the body, and how dysregulation in one organ system can affect other body systems.

16. Students have usually heard about subdural hematomas, and the presentation of material on the meninges provides a good opportunity for discussion of this condition. This is also a good time to explain where an epidural anesthetic would be placed.

Key point: These examples help students to visualize the layers of the meninges, along with their protective functions.

17. Share with students the mnemonic device On Occasion, Our Trusty Truck Acts Funny— Very Good Vehicle Anyhow, used for memorization of the 12 pairs of cranial nerves.

Key point: This mnemonic device requires a bit of explanation, but it is still useful for memorizing the cranial nerves.

18. Ask the students to tell you all the things that they think would happen if they were faced with a sudden, stressful situation, and list their responses on the board. Relate their responses to the fight-or-flight mechanism of the sympathetic division of the autonomic nervous system, and then point out that the parasympathetic division is charged with the responsibility of bringing all of these physiological changes back to normal.

Key point: This discussion allows students to understand the different roles of the sympathetic and parasympathetic divisions. Discussion of interventions such as biofeedback, meditation, and others can be discussed here as well.

19. Discuss the relationship of spinal nerves to the vertebrae. Make sure to remind students that while a normal human has seven cervical vertebrae, he or she will have eight cervical nerves.

Key point: Vertebrae are singular, and spinal nerves are paired. The first pair of cervical nerves arises superior to the first cervical vertebra.

20. Describe autism and all of its various types and treatments. Discuss the debunked myth regarding the MMR vaccine and autism.

Key point: Autism is a spectrum disorder that has multiple etiologies. There is no evidence that vaccinations can lead to the disorder, yet this myth has been propagated by nonscientists. This topic can be a great review of the scientific method as an important research tool.

21. List the conditions that have been treated (or are currently treated) by a partial lobotomy.

Be sure to indicate the success rate for each. Go through the history of the frontal lobotomy (Phineas Gage). A good example of the results of a frontal lobotomy can be found in the movie One Flew Over the Cuckoo’s Nest.

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Key point: Students can associate the changes in brain function with removal of parts of brain regions.

22. Discuss causes, symptoms, and treatment of concussions, and contrast them with contusions. Discuss the different treatment/recovery strategies for children and teens versus adults.

Key point: All students have heard of someone having a concussion or may themselves have experienced one, making this a relevant topic.

23. Discuss the severity of a ruptured brain aneurysm and why it is often fatal.

Key point: This injury illustrates the brain’s immense need for glucose and oxygen, and that deprivation of either can lead to brain death very quickly. As well, the students can appreciate how brain tissue is easily damaged if exposed directly to blood.

24. Discuss phantom limb sensation.

Key point: Phantom limb sensation occurs when patients experience sensation, such as pain, itch, tingling, or pressure in an extremity that is no longer there, such as an amputated arm. Current research is investigating two hypotheses: The first is that there are lasting representations of the phantom limb in the sensory cortex; the second suggests that there is reorganization or plasticity of the somatosensory cortex that leads to this sensation.

Classroom Demonstrations and Student Activities Classroom Demonstrations 1. To demonstrate the speed at which the brain is able to process sensory information and react to the environment, show how quickly a reaction can take place. A good demonstration is throwing a ball softly to a student without prior warning. (This can be combined with lecture hint #1.)

2. Demonstrate a knee-jerk reflex. Ask for a student volunteer to come to the front of the class to assist you with the demonstration. Tap his or her knee with a reflex hammer and note the response. If the student is nervous and appears to be holding the knee still, create a distraction by asking him or her to look to the side at a classmate, then to tap his or her own knee and note the difference in response.

3. Demonstrate a few other reflexes commonly used as diagnostic tools in medicine, such as Babinski’s reflex, the biceps reflex, and Chaddock’s reflex.

4. Take a sheet of paper and have students note the length. Start crumpling the paper and have students note that the paper is shorter, and then crumple up the paper further to demonstrate how the same amount of paper (analogous to brain tissue) can take up less space. Relate this to the concept that animals with higher mental capacity have more “wrinkled” brains. Have on hand for demonstration a human brain and other animal brains/models, such as those of a sheep and a mouse. Students will be able to directly observe more gyri and sulci and also a higher brain size to body size ratio.

5. Use a three-dimensional model of a neuron to point out structural characteristics and organelles of nerve cells. Use it in conjunction with a micrograph of a neuron.

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6. Bring in an insulated wire with sections missing and a bare, uninsulated wire to demonstrate myelination and the process of saltatory conduction and its advantages.

7. Use a spinal cord model to illustrate the way in which the spinal nerves originate from the dorsal and ventral roots and then split into rami.

8. Use a model or picture of the sciatic nerve to discuss why pregnant women experience sciatica.

9. Discuss EEGs and their use with a printout of the different types of brain waves and point out their characteristics.

10. Invite a pharmacist to discuss the effects of selected drugs on the brain and nervous system. Include some of the more common street drugs, such as alcohol and cocaine, on the discussion list.

11. Demonstrate a TENS Unit (transcutaneous electrical nerve stimulation unit), which reduces pain in a manner similar to “scratching an itch.”

Student Activities 1. Have students clasp their hands. Ask them whether they have the thumb of their left hand or their right hand on top, and whether this correlates with their understanding of which hemisphere of their brain is dominant.

2. Have students hold their index finger and thumb together on each hand, then touch the two hands together to form a small diamond between index fingers and thumbs. Have students focus on an object in the diamond with both eyes open. Close first one eye and then the other without moving your head or hands. Determine which eye is dominant based on the eye that is actually focused on the object in the diamond.

3. Provide full and cross-sectional drawings of the brain for students to color and label. An extension of this exercise is to call out specific brain functions and ask students to point to the area of the brain responsible for the function.

4. For students to better understand the motor homunculus, have them “probe” the motor cortex, using this PBS website: www.pbs.org/wgbh/nova/mind/probe.html 5. Have students explore some optical illusions and their explanations using this PBS website: www.pbs.org/wgbh/nova/mind/games.html 6. Have the students draw and label the ventricles of the brain.

7. Have students go to www.biointeractive.org/classroom-resources/neurophysiologyvirtual-lab, where electrical activities of neurons can be recorded, and neuron identity type can be determined through the results.

8. Provide reflex hammers and instructions for producing the patellar, Achilles stretch, and plantar reflexes. Have students work in pairs to produce and observe these reflexes. Have students then draw the pathway of a simple and complex reflex arc.

9. Have students measure their heart and breathing rates at rest. Without giving any warning, blow a shrill whistle to produce a startle response in the members of the class. Have students retest their heart and breathing rates. Then, initiate a class discussion on the effects of the sympathetic division of the autonomic nervous system by asking students to indicate which of their body organs were affected by the sound and what the organ response was.

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10. Provide two hard-boiled eggs per group, each egg in a quart-size self-sealing bag. Have students pour water into one bag, place an egg in it, and then add salt until the egg is suspended. The other container will only contain the egg. Drop each bag outdoors from the same height to show how CSF works for brain buoyancy and protection of the brain from insults.

11. Have students practice conducting cranial nerve tests.

12. Ask students to bring in articles from magazines or from the Internet from scientifically reputable sources such as major news media outlets or scientific journals that discuss research about sex differences in the brain. Discuss the articles in class.

13. Ask students to bring in articles from magazines or from the Internet that discuss the role of neurotransmitters in depression and in brain disorders, such as Parkinson’s, or articles that cover the effect that common street drugs have upon them. Discuss the various articles.

14. Show a 10-minute clip of the films Lorenzo’s Oil, Regarding Henry, or Awakenings and engage the students in a class discussion.

15. Show the PBS video How Smart Can We Get? and have students discuss related concepts discussed in the video.

16. Have students dissect a sheep brain and compare and contrast it with a plastic human brain model.

Media See page 164 for a listing of media distributors.

1. Nervous system (Bozeman Science: 18 min., 2011, www.bozemanscience.com/nervoussystem). A discussion of brain laterality and neuron structure and function are discussed in this podcast.

2. A New Way to See the Brain (PBS: 6 min., 2015, www.pbs.org/wgbh/nova/body/NewWay-to-See-Brain.html). Using expansion microscopy.

3. Mapping the Brain (PBS: interactive website, 2012, www.pbs.org/wgbh/nova/assets/swf/1/mapping-the-brain/mapping-the-brain.html). Interactive site where students can choose between current imaging techniques such as fMRI, PET, DTI, and so on to understand what can be visualized by each technique.

4. Lorenzo’s Oil (129 min., 1992, VHS, DVD). Documents the real-life story of Lorenzo Odone, who has a rare myelin-degenerating terminal disease called adrenoleukodystrophy (ALD), and his parents (Augusto and Michaela), who collide with doctors, scientists, and support groups in their quest to develop an oil from the combination of two fats extracted from olive oil and rapeseed oil to prevent the body’s production of very long-chain fatty acids whose buildup leads to demyelination. See www.myelin.org/aldadrenoleukodystrophy/ for more information.

5. How Smart Can We Get? (PBS: 60 min., 2012, DVD). Discusses the history of Einstein’s brain, the concept of intelligence, memory, and the impact of stress on memory.

6. I Have Tourette’s but Tourette’s Doesn’t Have Me (HBO: 27 min., 2005, DVD). This documentary explores the lives of children suffering from Tourette’s syndrome. In the ..

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film, a wide variety of tics and the ways that the kids cope with being “different” are explored.

7. How Does My Brain Work? (TED Talks, 2011, 130 min. total, Internet video). This TED-curated video selection discusses an introduction to brain function and moves to cutting- edge technologies used to study the brain: www.ted.com/playlists/1/how_does_my_brain_work 8. Sylvius 4 Online: An interactive atlas and visual glossary of human neuroanatomy. www.learninglink.oup.com/access/sylvius

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CHAPTER

8

Special Senses

Chapter Summary The special senses keep us informed as to what is going on in our external world. Sense receptors are found in large, complex sensory organs like the eye or in localized clusters of receptors like the taste buds. This chapter focuses on the special senses: vision, hearing and balance, olfaction, and gustation. Each of the sensory organs is described individually, but the text also emphasizes that we experience the world as a blending of the effects of various stimuli, detected by multiple special sense structures.

The eye is the first of the sense organs to be presented. External eye anatomy is described, along with its accessory structures. Next, internal eye structures like the wall of the eyeball and the structures contained within, along with the retina, lens, and humors, are explained in detail. The refractive properties of the eye are presented next, followed by a description of the visual pathways to the brain and an explanation of eye reflexes, along with some visual defect conditions.

The ear and its role in hearing and balance are discussed next in the chapter. The anatomy of the ear begins with the outer ear structures, followed by the middle and inner ear. Static and dynamic equilibrium, detected by the vestibular apparatus, are described and differentiated. The mechanism of hearing is explained in detail, with emphasis on the role of the hair cells found in the organ of Corti, followed by a discussion of some of the more common hearing and equilibrium deficits.

The chemical senses of taste and smell are presented in the final section. Chemoreceptors involved in both taste and smell respond to chemicals in solution. In the case of smell, olfactory receptors located in the roof of each nasal cavity are sensitive to a wide range of chemicals, whereas taste receptors located in the oral cavity are identified as five basic types: sweet, sour, bitter, salty, and umami. Because taste and smell are linked by their response to chemicals and enzymatic reactions in solution, students quickly understand the reason why food seems to have no taste when they have a cold, and why salty food tastes sweet when held in the mouth for 20 to 30 seconds. The chapter concludes with other examples of homeostatic imbalance related to the special senses.

Suggested Lecture Outline PART I: The Eye and Vision (pp. 273–284) I. 8.1 Anatomy of the Eye (pp. 273–281) A. 8.1a External and Accessory Structures B. 8.1b Internal Structures: The Eyeball 1. Layers Forming the Wall of the Eyeball a. Fibrous Layer ..

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b. Vascular Layer c. Sensory Layer 2. Lens

II. 8.2 Physiology of Vision (pp. 281–284) A. 8.2a Pathway of Light through the Eye and Light Refraction B. 8.2b Visual Fields and Visual Pathways to the Brain C. 8.2c Eye Reflexes

PART II: The Ear: Hearing and Balance (pp.

284–292) I. 8.3 Anatomy of the Ear (pp. 285–286) A. 8.3a External (Outer) Ear

TEACHING TIP For each of the special senses, be sure to account for enough time to go through how stimuli from the environment are detected and the information relayed to the CNS. These pathways are complicated, and students need to be guided through, rather than being required to learn all of the steps completely on their own.

B. 8.3b Middle Ear C. 8.3c Internal (Inner) Ear

II. 8.4 Hearing (pp. 286-289) III. 8.5Equilibrium (pp. 289–292) A. 8.5a Static Equilibrium B. 8.5b Dynamic Equilibrium

C. 8.5c Hearing and Equilibrium Deficits (pp. 291– 292)

PART III: Chemical Senses: Smell and Taste (pp. 292–295) I. 8.6 Olfactory Receptors and the Sense of Smell (pp.

292–293) II. 8.7 Taste Buds and the Sense of Taste (pp. 293–295)

PART IV: Developmental Aspects of the Special Senses (pp. 295–296) Note: For a list of Key Terms for this chapter, please go to Mastering A&P > Study Area > Additional Study Tools > Key Terms > Chapter 8.

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MEDIA TIP Sensation and Perception (ACBP: 30 min., 2001).

From the Discovering Psychology series, this program illustrates how information about the world is gathered by sensory receptors, and is then transmitted to and interpreted by the brain.

Watch at www.learner.org/series/disc overingpsychology/sensation-andperception/ Another fun discussion opener is the following video on the sensation of taste: The Science of Picky Eaters (PBS, 53 min., 2009). The genetics behind picky eaters are discussed, which can lead to a lively class discussion. Watch at www.pbs.org/wgbh/nova/bo dy/science-picky-eaters.html

8-1

When provided with a model or diagram, identify the accessory eye structures, and list the functions of each.

8-2

Name the layers of the wall of the eye, and indicate the major function of each.

8-3

Explain how the functions of rods and cones differ.

8-4

Define blind spot, cataract, and glaucoma.

8-5

Trace the pathway of light through the eye to the retina.

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8-6

Discuss the importance of an ophthalmoscopic examination.

8-7

Describe image formation on the retina.

8-8

Define the following terms: accommodation, astigmatism, emmetropia, hyperopia, myopia, and refraction.

8-9

Trace the visual pathway to the visual cortex.

8-10 Discuss the importance of the convergence and pupillary reflexes.

8-11 Identify the structures of the external ear, middle ear, and internal ear, and list the functions of each.

8-12 Explain the function of the spiral organ of Corti in hearing.

8-13 Define sensorineural deafness and conductive deafness, and list possible causes of each.

8-14 Explain how a person is able to localize the source of a sound.

8-15 Distinguish between static and dynamic equilibrium.

8-16 Describe how the equilibrium organs help maintain balance.

8-17 Describe the location, structure, and function of the olfactory and taste receptors.

8-18 Name the five basic taste sensations, and list factors that modify the sense of taste.

8-19 Describe changes that occur with age in the special sense organs.

Resources for Teaching Online Discussion Board Topic: Homeostatic Imbalance—Cataracts In the textbook on page 280, the Homeostatic Imbalance section discusses cataracts, where the lens of the eye becomes hardened and opaque. Engage your students by using the following discussion questions in lecture or by posting them to the discussion board on your course management system.

Discussion Questions 1. How do cataracts affect vision?

2. How are cataracts diagnosed?

3. How are cataracts treated in early stages versus advanced stages?

4. Describe the two main types of cataract surgery.

Potential Student Responses: 1. In a normal eye, cells called lens fibers are arranged in a pattern much like layers of an onion. As aging takes place, the lens fibers tend to lose their regular arrangement, and/or there is clumping of protein in the cytoplasm of these cells that scatters the light, rather than allowing the eye to absorb it. When this happens, the sharpness of the viewed objects is lost and blurred vision results. Also, a yellow-brown pigment develops in the lens, and tints the vision brown. Progression of blurry vision and tinting can eventually cause loss of vision.

2. Some common tests include a check for visual acuity at different distances by having the patient read an eye chart, examination of the retina and the optic nerve in dilated eyes, slit ..

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lamp examination with the cornea and other structures magnified and examined in illuminated sections, and measuring internal eye pressure (tonometry).

3. In early stages, eyeglasses, sunglasses, brighter lighting, and magnifying lenses are used to enhance impaired vision. In later stages, surgery is needed to replace the lens with an artificial one. The artificial lens is called an intraocular lens (IOL).

4. There are two traditional types of lens surgery: phacoemulsification and extracapsular surgery. Phacoemulsification uses ultrasound to break up the lens, and it is sucked out from a slit on the side of the cornea. Extracapsular surgery also involves creating a slit on the side of the cornea, but it removes the core of the lens, and then the rest is suctioned out. The lens is replaced by an intraocular lens (IOL). If there are other eye conditions present, then the lens may not be replaceable and either soft contacts or glasses will be prescribed. In the past couple of years, a surgery technique called “femtosecond laser surgery” has been gaining popularity and is being used to remove cataracts with precise laser incisions; incisions are made in the cornea and a specific intraocular lens is inserted, such as a multifocal lens for near and far vision.

Investigate Online Take learning a step further by searching for relevant research articles on the Web. Visit science websites, such as those listed below, and begin by searching for key terms such as cataracts, intraocular lens, secondary cataract, congenital cataract, traumatic cataract, and radiation cataract, and see how what you’re learning in the course applies to science and medicine today. www.sciencedaily.com www.scientificamerican.com www.the-scientist.com www.ncbi.nlm.nih.gov/pubmed aao.org

Study Tips Direct students to the Study Tips feature located in the front of the book.

Mastering A&P Numerous items from Mastering A&P can be demonstrated in class, assigned as homework, or encouraged as study materials. These include practice tests and quizzes, animations and videos, Interactive Physiology (IP), Dynamic Study Modules, Audio Journeys, Practice Anatomy Lab (PAL), PhysioEx, flashcards, glossary, key terms, and more.

Animations and Videos The following animations and videos are relevant to this chapter:

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Bone and Dissection Videos > Cow and Sheep Dissection > Cow Eye: Anterior Segment; Cow Eye: External Anatomy; Cow Eye: Posterior Segment

Practice Anatomy Lab (PAL)3.1: Including Mobile Flashcards The following sections of PAL3.1 are relevant to this chapter:

Human Cadaver > Nervous System > Special Senses

Anatomical Models > Nervous System > Special Senses

Histology > Special Senses

Additional Study Tools The following video is relevant to this chapter:

Focus on Careers > Physical Therapy Assistant

Lecture Hints 1. Use dissectible eye models and/or sheep eyes placed on an ELMO during presentation of eye anatomy to help students visualize the structures of the eye as they are presented.

Key point: It is important to emphasize the layering of the tunics and other structures of the eye prior to discussing the mechanisms involved in refraction. Students are often surprised by the delicate nature of the retina when a sheep eye is dissected, thus making more relevant the gravity of a detached retina.

2. Point out the location of the lacrimal gland in the upper, outer canthus of the eye.

Students frequently think that tears come from the lacrimal canal itself and are generally surprised to find that they wash across the eye, then empty into the lacrimal canal at the lower, inner canthus.

Key point: This is a good opportunity to discuss the protective properties of lysozymes in tears, as well as to talk about other benefits of tears, including lubrication and emotional release.

3. Discuss conjunctivitis, or pinkeye. Most students have seen the redness associated with this condition and it helps them visualize the location of this mucous membrane. Discuss the main ways this infection is acquired.

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Key point: The conjunctiva is a delicate mucous membrane that lines the eyelids and covers the anterior portion of the eyeball. Infection most often is bacterial or viral in nature; emphasize that antibiotics work only on bacterial infections. Infection can be easily contracted—for example, by touching an infected object, such as a doorknob, and then rubbing the eye.

4. Point out that the cones in the eye are sensitive to blue, green, and red wavelengths, not yellow, red, and blue, as students often expect. Discuss this in relation to traffic lights and the difficulty that a color-blind person might have in differentiating between red and green.

Key point: Color blindness exhibits itself in a variety of ways, depending on the cones that are absent. Note that it is an X-linked characteristic of the 23rd chromosome; thus, it occurs primarily in males. An XY male can manifest color blindness while receiving a defective X chromosome from his mother, whereas an XX female must receive a defective X from both her mother and father to manifest color blindness.

5. Explain why checking for pupils of equal diameter and documenting Pupils Equal and Reactive to Light and Accommodation (PERLA) are standard neurological signs.

Key point: Pupils that are unequal in diameter or that fail to adjust their shape when a bright light is flashed in them can be indicative of such conditions as cerebral hemorrhage, which puts pressure on the optic nerve.

6. Students enjoy a detailed discussion of the principles of accommodation, particularly related to the conditions of myopia and hyperopia with which they are familiar. Point out that myopia means “near vision” (i.e., the person is able to see close up), and hyperopia means “far vision” (i.e., the person is able to see at a distance). Also explain that age leads to a specific type of hyperopia called presbyopia, or old-age vision. The often-read novel Lord of the Flies describes a near-sighted boy who starts fires with his glasses.

However, a light-dispersing concave lens used to correct myopia could never start a fire, as only a convex (thick in the middle) lens used to correct for hyperopia could concentrate light rays to start a fire.

Key point: Eyeballs that are either too long or too short, or lenses that do not accommodate well, are homeostatic imbalances resulting in conditions outside the normal emmetropia.

7. Relate to students that because incoming light is refracted by a combination of both the cornea and the lens, laser eye surgery (LASIK—laser in situ keratomileusis) to correct myopia and hyperopia needs to involve adjustment only of the curvature of the outer cornea (not the lens).

Key point: It is much easier to surgically reduce the curvature of the cornea to correct for myopia than to build up the curvature of the cornea to correct for hyperopia. Surgical correction for myopia has been done for a longer time and is thus more reliable than correction for hyperopia.

8. Discuss orthokeratology for astigmatism management.

Key point: Orthokeratology is essentially analogous to a retainer, but they are retainers for the eye instead of the mouth. For those with moderate amounts of astigmatism, where the cornea is irregularly shaped, rigid gas-permeable contact lenses can be worn overnight or for specified periods of time, and the cornea can be temporarily reshaped for 89

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better focusing without the contacts. Like retainers, these contacts also appear to discourage the astigmatism from progressing if worn daily for the specified amount of time.

9. Discuss corneal and lens transplants with students and explain their high success rate.

Key point: Because both of these structures are avascular, they are not as easily rejected by the body due to lack of immune cells in the area.

10. Explain that the eye and the ear are not only receptors for light and sound impulses but are also energy transducers because they convert light and sound energy into the electrical energy of an action potential.

Key point: It is important for students to understand that it is the electrical impulse that is interpreted by the brain, and if the visual and auditory interpretive areas of the brain are damaged, the person will neither see nor hear despite functioning sensory receptors.

11. Use dissectible ear models during the presentation of ear anatomy to help students visualize the structures of the ear as they are presented.

Key point: It is helpful to students to visualize the structures of the ear that are important for hearing and those that are important for equilibrium. Using these models will help students visualize where ear infections can take place (e.g., “swimmer’s ear” versus middle ear infections).

12. Discuss how hearing aids work to correct hearing deficiencies. Explain to the students why not all forms of deafness can be corrected in this fashion. Also discuss cochlear implants and how they work.

Key point: Once students understand how hearing occurs, they can appreciate how a hearing aid helps with sound transmission. Hearing aids amplify sounds, while cochlear implants directly stimulate the auditory nerve.

13. Discuss the auditory (eustachian) tube and its normal role in pressure equalization.

Students are quite familiar with the “pop” of their eardrum that precedes improved hearing when changing altitude while in a car or in a plane or scuba diving. Explain how chewing gum or yawning brings this about. Also explain the physiological and medical implications related to insertion of pressure equalizing (PE) tubes in children.

Key point: Yawning or chewing gum forces air into the auditory tube, which balances the pressure between the outer ear and middle ear. In children, this tube is shorter and more horizontal, often leading to frequent middle ear infections (otitis media). Insertion of PE tubes helps drain the middle ear and keeps the pressure equal until the auditory tubes elongate and become more vertical as the child ages.

14. Discuss some of the more common conditions leading to vertigo (dizziness), such as Ménière’s syndrome, otitis media, motion sickness, and diplopia.

Key point: Students are amazed by the variety of conditions that can result from a homeostatic imbalance of the inner ear and other structures important in balance and equilibrium.

15. Clearly differentiate between static equilibrium and dynamic equilibrium, as students frequently think of “balance” as a single mechanism.

Key point: Static equilibrium helps to keep the body informed of the position of the head in space (e.g., up or down), whereas dynamic equilibrium helps us to orient ourselves to ..

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the three planes of space in which our bodies move. They act together to keep us balanced and “on an even keel.”

16. Ask students to describe a scent that triggers a specific memory for them, such as the smell of newly baked bread or a certain perfume. Note the connection between the olfactory senses and long-term memory. For example, students can learn anatomy from interactive dissection websites such as frogguts.com, but it may not reside in the longterm memory as well as actual “live” dissections because the wonderful smell of the specimen is absent.

Key point: The olfactory senses have a strong link to memory, because the olfactory bulbs are part of the limbic system, which oversees emotion and memory. This is an excellent example of how the brain interprets sensory input and even commits some of the messages to our memory banks.

17. Discuss where the taste buds are located on the tongue. Emphasize that most taste buds can detect more than one taste sensation rather than only one of the five.

Key point: There is a misconception that there are distinct, discrete locations for taste buds for sweet, sour, bitter, salty, and umami that can be diagrammed on a “tongue map.”

Many of the papillae have receptors for more than one taste, although there may be some clustering of papillae that may have more receptors for a particular taste.

18. Make reference to a “bitter pill,” and point out that it is the taste buds’ ability to detect alkaloids that accounts for this taste. Further explain that sour within the chemistry of cooking is a result of hydrogen ion detection (acidity), salty is metal detection, savory is amino acid detection, and sweet is, of course, sugar detection.

Key point: Correlating taste sensations with their chemical counterparts helps students to understand the way in which these various sensations can blend to make eating such an enjoyable experience.

19. Umami is considered to be the fifth taste sensation, along with sweet, sour, bitter, and salty. This taste sensation is due to the recognition in foods by the taste buds of the amino acid L-glutamate. Translating from Japanese as “deliciousness” or “savory,” this taste is often found in protein-rich foods.

Key point: Originally described in 1909 by a Japanese scientist, this taste sensation has only recently come into acceptance, being “rediscovered” in the Western world in 2000, after it was shown that there are unique G-protein–driven receptors for L-glutamate. It is still not widely known about by the general public.

Classroom Demonstrations and Student Activities Classroom Demonstrations 1. Use three-dimensional models of the eye and ear to demonstrate the structural characteristics of these special sense organs.

2. Use a three-dimensional model of the nose, and also a human skull where the cribriform plate is visible, to show the pathway of smell input and to show how information from the nose can be transmitted to the brain.

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3. Use models to show the six extrinsic eye muscles and the movements controlled by each.

Call out an eye muscle and have students perform the movement for which the muscle is responsible.

4. Dissect the eye of a cow or sheep so that students can observe the internal eye structures.

Point out how fragile the retina is and draw attention to the fact that it is attached at a single point—the optic disc. Also, show the lens to the students and discuss how it would look with cataracts. Point out the tapetum lucidum and explain why it is not present in humans.

5. Spray cologne into the air, and ask students to raise their hands when they first smell it.

Then continue with your lecture, and approximately 5 minutes later, ask how many can still smell the cologne. Use this as a jumping-off point for your discussion on adaptation of the sensory apparatus. Also remind students of the concept of diffusion when you first sprayed the cologne.

6. Demonstrate how the Rinne test and the Weber test using tuning forks can be used to determine localization of hearing loss.

7. Obtain ear tubes made for both short-term use and for long-term use and note the differences in structure and their intended length of use in the tympanic membrane. Also show a video on the procedure such as the online video at emedicine.medscape.com/article/1890757-overview#a3

Student Activities 1. To help explain that the fovea centralis is the area of sharpest vision, have the students all look at the same picture in their textbook. Ask them to notice any adjusting they do to bring the picture into sharper focus, such as moving the book or the position of their head. Point out that the fovea centralis exclusively contains cones.

2. Perform selected vision tests, including visual acuity using a Snellen chart, color deficiency using the Ishihara test for color blindness, and locating the blind spot.

3. Provide the students with a list of the refracting parts of the eye. Have them rearrange the list to correspond with the sequence through which light would travel as it moves from the outside to the interior of the eye, prior to stimulating the rods and cones.

4. Provide the students with a list of the vibrating parts of the ear. Have them rearrange the list to correspond with the sequence through which sound would travel as it moves from the outside to the interior of the ear, prior to stimulating the hair cells.

5. Have students diagram the pathway of hearing through the ear to the brain, including how sound energy is translated from vibrational energy to electrical impulses.

6. To examine the important connection between smell and taste in the identification of foods, select one student to be the subject in the following experiment. The student closes his or her eyes and pinches the nostrils closed. Then he or she should attempt by taste alone to distinguish mozzarella cheese from a hard-boiled egg white (cut into pieces of similar size), taking a sip of water between samplings. If the attempt is unsuccessful, the nostrils should be released and the test conducted again. Other foods also work well, such as apples and raw potatoes, and are suitable for students who may be vegan.

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7. Have students put something salty, sweet, or sour on different parts of the tongue to show that there is not one specific place on the tongue that will detect salty (or sweet, sour, etc.).

8. Have students put some blue food coloring on a cotton swab and then rub the swab on their tongue. Then have students look in a mirror. The tongue should now have a blue tint; however, the fungiform papillae should remain pinkish in color. In this way the students can visualize their taste buds more clearly.

9. Have students taste phenylthiourea (PTC) paper; tasting the paper as bitter or not is genetic. Have students hypothesize as to how genetics affect whether or not the bitterness is detected.

10. Show examples of optical illusions and give students an opportunity to study and explain them. Use kids.niehs.nih.gov/games/riddles/illusions/index.htm as a launching point for some illusions on the Web. 11. Have students create models of how otoliths work to determine orientation in space. This can be done with liquid, uncooked beans or rice, or sand/gravel in empty water bottles.

12. Have students wear vision-impairment glasses that mimic such conditions as cataracts, glaucoma, macular degeneration, retinopathy, and detached retina and have them carry out daily tasks such as eating a bowl of cereal, reading the newspaper, and so on. This exercise can be modified to have students wear alcohol-impairment goggles as well.

Media See page 164 for a listing of media distributors.

1. The Structure of the Eye (Khan Academy: 11 min., 2014, www.khanacademy.org/science/health-and-medicine/nervous-system-and-sensoryinfor/sight-2014-03-27T18:45:34.237Z/v/vision-structure-of-the-eye). Brief tutorial of eye structure.

2. The Senses (FHS: 20 min., 1995, VHS, DVD, 3-year streaming webcast). From The New Living Body series, this program demonstrates how the senses of sight and balance operate, as well as how they interact with each other.

3. The Miracle Worker (106 min., 1962, VHS, DVD). The true story of deaf-blind Helen Keller and her teacher, Anne Sullivan, who taught her to communicate.

4. Tour the Tongue (PBS: interactive website, 2009, www.pbs.org/wgbh/nova/body/tonguetaste.html). Interactive website that explains the five taste sensations.

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CHAPTER

9

The Endocrine System

Chapter Summary The endocrine system is the slow-acting communication system of the body. Second in command to the nervous system (the fast-acting homeostatic control system) that oversees it, the endocrine system regulates the homeostatic processes of reproduction, growth and development, body defenses, metabolic processes, and blood chemistry. Bloodborne communication chemicals called hormones are the effectors of the endocrine system. Hormones circulate in the blood until reaching the target tissues upon which they are designed to act. They then bind with the awaiting cell receptors and immediately begin to influence the internal machinery of those cells.

In this chapter, the mechanisms of hormone action are discussed first, with a differentiation between the actions of steroidal and nonsteroidal hormones, and the location of their receptors on/in their target cells. Next, the chapter presents the negative feedback mechanisms that control hormone release. It then explores the hormonal, humoral, and neural stimuli that initiate an endocrine response.

Following the discussion of endocrine stimuli, the chapter presents the major endocrine organs and their hormones’ main actions and regulatory functions. The hypothalamus, which plays an important role in nervous system functioning, is also noted for its major role in endocrine control, based upon its relationship with the pituitary gland. The chapter then describes the complexity of the pituitary gland, with its separate anterior and posterior lobes.

The posterior lobe functions as a storage and release site for two hormones that are made in the hypothalamus and transported through hypothalamic axons, while the anterior lobe manufactures and secretes its own hormones. The pineal gland and its secretion of melatonin is then discussed. The thyroid is presented next, and its role in both metabolism and blood calcium levels is addressed, followed by a discussion of the thyroid’s counterbalancing relationship to the parathyroid glands in blood calcium regulation. The hormones of the adrenal glands, both cortical and medullar portions, are described in relation to their roles in the longand short-term stress responses. The islet cells of the pancreas and the hormones they produce are then discussed, along with their respective interactions with blood glucose levels. A description of the thymus hormones precedes the section on the gonadal hormones of the ovaries and testes.

Finally, the chapter covers hormones produced by other body tissues, as well as hormones produced by the placenta. It is important to note that some endocrine organs, such as the pancreas and gonads, also may have additional and separate exocrine functions. The major developmental aspects of the endocrine system, including its role in menopause, conclude the chapter.

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Suggested Lecture Outline I. 9.1 The Endocrine System and Hormone Function—An Overview (pp. 303–306) A. 9.1a The Chemistry of Hormones (p. 303)

TEACHING TIP

B. 9.1b Hormone Action (pp. 303–304) 1. Direct Gene Activation 2. Second-Messenger System

It is critical for the students to understand the “big picture” of how hormones function. Introduce the function of each hormone initially, and then draw a concept map from the initial stimulus that induces secretion of a hormone to the target organ and the effect upon that organ. Talk about how feedback mechanisms signal when to cease or increase hormone secretion. Mention to students the role of the hypothalamus in producing many tropic hormones. The concept map will help students understand the integral role of the endocrine system in the process of homeostasis.

C. 9.1c Stimuli for Control of Hormone Release (pp.

305–306) 1. Hormonal Stimuli 2. Humoral Stimuli 3. Neural Stimuli

II. 9.2 The Major Endocrine Organs (pp. 306–323) A. 9.2a Pituitary Gland and Hypothalamus (pp. 307–310) 1. Pituitary–Hypothalamus Relationships 2. Posterior Pituitary and Hypothalamic Hormones 3. Anterior Pituitary Hormones B. 9.2b Pineal Gland (pp. 310-311) C. 9.2c Thyroid Gland (pp. 311–312) D. 9.2d Parathyroid Glands (pp. 313–314) E. 9.2e Thymus (p. 314) F. 9.2f Adrenal Glands (pp. 314–318) 1. Hormones of the Adrenal Cortex 2. Hormones of the Adrenal Medulla G. 9.2g Pancreatic Islets (pp. 318–319) H. 9.2h Gonads (pp. 319–321) 1. Hormones of the Ovaries 2. Hormones of the Testes

III. 9.3 Other Hormone-Producing Tissues and Organs (pp. 323–324) IV. 9.4 Developmental Aspects of the Endocrine System (pp. 323, 326) Note: For a list of Key Terms for this chapter, please go to Mastering A&P > Study Area > Additional Study Tools > Key Terms > Chapter 9.

Learning Objectives

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9-1

Define hormone and target organ.

9-2

Describe how hormones bring about their effects in the body.

9-3

Explain how various endocrine glands are stimulated to release their hormonal products.

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9-4

Define negative feedback, and describe its role in regulating blood levels of the various hormones.

9-5

Describe the difference between endocrine and exocrine glands.

9-6

On an appropriate diagram, identify the major endocrine glands and tissues.

9-7

List hormones produced by the endocrine glands and discuss their general functions.

9-8

Discuss ways in which hormones promote body homeostasis by giving examples of hormonal actions.

9-9

Describe major pathological consequences of hypersecretion and hyposecretion of the hormones considered in this chapter.

9-10 Describe the functional relationship between the hypothalamus and the pituitary gland.

9-11 Indicate the endocrine role of the kidneys, the stomach and intestine, the heart, and the placenta.

9-12 Describe the effect of aging on the endocrine system and body homeostasis.

Resources for Teaching Online Discussion Board Topic: Homeostatic Imbalance—Diabetes Insipidus In the textbook on page 308, the Homeostatic Imbalance section introduces the condition of diabetes insipidus, which is caused by the hyposecretion of antidiuretic hormone (ADH). Major symptoms are excessive thirst and excessive urination. Engage your students by using the following discussion questions in lecture or by posting them to the discussion board on your course management system.

Discussion Questions 1. Discuss the similarities and differences between diabetes insipidus and diabetes mellitus.

2. What are some treatment strategies for diabetes insipidus?

3. What are the genetic and nongenetic causes of diabetes insipidus?

4. What are the types of diabetes insipidus?

Potential Student Responses 1. The symptoms of excessive thirst and urination (diabetes originates from the Greek diabainein, which means “to siphon” or “to pass through”) are common for both types of diabetes. However, this is where the similarities end. The lack of ADH secretion in diabetes insipidus is usually due to destruction of the posterior pituitary or to resistance to ADH. There are elevated blood glucose levels in patients with diabetes mellitus, due to insulin resistance, which is not found in patients with diabetes insipidus. Patients with diabetes insipidus may also show signs of dehydration, because the body cannot retain enough of the imbibed water.

2. If the diabetes is due to hyposecretion of ADH, a synthetic version can be administered to restore water balance in the body. If the kidneys are nonresponsive to ADH, then thiazides, although diuretics themselves, are able to lower urine output in these patients.

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3. Central diabetes insipidus (DI) that is inherited tends to be autosomal dominant. Nephrologic DI tends to be X-linked or could be passed autosomally, through either dominant or recessive routes. Nongenetic causes of DI are trauma to the head, neurosurgery consequences, or tumors.

4. Central diabetes insipidus results from pituitary damage, which directly impacts ADH. Nephrogenic diabetes insipidus results from an inability of the kidneys to respond to ADH signals. Dipsogenic diabetes insipidus results from damage to the hypothalamic thirst mechanism. Gestational diabetes insipidus occurs during pregnancy, during which maternal ADH is destroyed by a placental enzyme.

Investigate Online Take learning a step further by searching for relevant research articles on the Web. Visit science websites, such as those listed below, and begin by searching for key terms such as central diabetes insipidus, nephrogenic diabetes insipidus, gestational diabetes insipidus, diabetes insipidus treatment, polyuria, polydipsia, and diabetes insipidus etiology and see how what you’re learning in the course applies to science and medicine today. www.sciencedaily.com www.scientificamerican.com www.the-scientist.com www.ncbi.nlm.nih.gov/pubmed www.nature.com/subjects/diabetes-insipidus

Study Tips Direct students to the Study Tips feature located in the front of the book.

Mastering A&P Numerous items from Mastering A&P can be demonstrated in class, assigned as homework, or encouraged as study materials. These include practice tests and quizzes, animations and videos, Interactive Physiology (IP), Dynamic Study Modules, Audio Journeys, Practice Anatomy Lab (PAL), PhysioEx, flashcards, glossary, key terms, and more.

Interactive Physiology (IP) The following sections of Interactive Physiology are relevant to this chapter: Endocrine System IP Anatomy Review Animation: Endocrine IP Animation: Mechanism of Hormone Activation: Direct Gene Activation IP Animation: Mechanism of Hormone Activation: Second Messenger System IP Animation: Hypothalamic-Pituitary Axis IP Animation: Response to Stress 97

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PhysioEx10.0 The following section of PhysioEx10.0 is relevant to this chapter:

Exercise 4: Endocrine System Physiology

Animations and Videos The following animations and videos are relevant to this chapter:

A&P Flix > Mechanism of Hormone Action: Second Messenger cAMP

BIO Flix > Homeostasis: Regulating Blood Sugar

Practice Anatomy Lab (PAL)3.1: Including Mobile Flashcards The following sections of PAL3.1 are relevant to this chapter:

Human Cadaver > Endocrine System

Anatomical Models > Endocrine System

Histology > Endocrine System

Cat > Endocrine System

Fetal Pig > Endocrine System

Lecture Hints 1. Describe the process of hormone attachment to its target organ as a lock-and-key mechanism.

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Key point: In order for the cells of target organs to respond to a particular hormone, the hormone must attach to specific receptors on the target cell’s surface (i.e., there must be a natural “fit”) for amino acid–based hormones. For example, antidiuretic hormone (ADH or vasopressin) will have no effect on the liver or heart, but will act upon the kidneys because they have receptor sites for antidiuretic hormone. Also discuss how the lock-andkey mechanism holds true as well for the steroid hormones that bind to their receptors within the cell. It is important to emphasize that although hormones travel throughout the bloodstream and can potentially impact every body tissue, they do not; a hormone effects changes only in those tissues that have receptors specific to that particular hormone.

2. Stress the structural and functional relationship between the nervous system and the endocrine system. The nervous system itself is responsible for acute, moment-to-moment homeostatic maintenance and also oversees the endocrine system, which is the important monitor for day-to-day homeostasis. Discuss the role of the hypothalamus as the regulator of the endocrine system.

Key point: The nervous and endocrine systems work together closely to coordinate and direct the key activities within the human body, and are considered the fast-acting and slow-acting communication systems, respectively. The endocrine system is primarily overseen by the hypothalamus in the brain. The hypothalamus manufactures and secretes many tropic hormones that impact the anterior pituitary and its hormone production. The hypothalamus also manufactures oxytocin and antidiuretic hormone.

3. Point out that the endocrine system is an excellent example of homeostasis and negative feedback. Use examples such as the counterbalancing effect between calcitonin of the thyroid gland and parathormone of the parathyroid glands in blood calcium regulation, as well as glucagon and insulin, both secreted by the liver for blood glucose homeostasis.

Key point: This is an excellent chapter in which to focus on feedback mechanisms, in particular, negative feedback. Most of the hormones use a negative feedback loop for regulation. However, oxytocin and prolactin secretion are good examples of positive feedback.

4. Discuss tropic hormones and explain the many instances in which hormones from one endocrine gland stimulate the production of hormones from another endocrine gland, which then act on other body organs and tissues. Specific examples include the hormones in the hypothalamic-pituitary-adrenal (HPA) axis, hypothalamic-pituitary-gonadal (HPG) axis, and hypothalamic-pituitary-thyroid (HPT) axis.

Key point: This is one of the most intriguing aspects of the endocrine system, and one that warrants particular attention because of its significance to overall body function. The brain oversees, and also receives feedback from, the endocrine system.

5. Present numerous examples of homeostatic imbalance as related to the endocrine system.

Use a series of opposites to help clarify the point, such as hypothyroidism versus hyperthyroidism and gigantism versus dwarfism.

Key point: Students can readily understand that too much or too little of a certain hormone might have opposite and often life-threatening effects. These examples help them to visualize the results of these types of hormonal imbalances.

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6. Discuss oxytocin and its significance in labor, delivery, and milk ejection. Explain that an “IV Pit” (intravenous synthetic oxytocin, called Pitocin) would be administered when women ready for childbirth cannot dilate sufficiently. Also, emphasize that this hormone is part of a positive feedback mechanism used by the body.

Key point: Oxytocin is important not only in labor, and during breastfeeding it can also help the mother bond with her baby, as it is also known as the “bonding” or “cuddle” hormone. Pitocin is regularly used in IV form, not only to induce labor but also to hasten labor and to help the uterus regain its postpartum shape after delivery.

7. Spend extra time outlining the connection between the hypothalamus and the anterior and posterior pituitary gland. This is an excellent opportunity to again show the intimate connection between the nervous and endocrine systems. Emphasize the endocrine tissue composition of the anterior pituitary and the nervous tissue composition of the posterior pituitary.

Key point: Students have often heard the pituitary referred to as the “master gland.” Emphasize that although the anterior pituitary produces numerous hormones, it releases those hormones in response to releasing or inhibiting hormones from the hypothalamus.

Further point out that the posterior pituitary does not make its own hormones but, rather, releases hormones made by the hypothalamus. Discuss how hormones are directly delivered by axons of hypothalamic neurons, while the anterior pituitary responds to hypothalamic hormones delivered through the bloodstream (through the hypophyseal portal system). Present the case that perhaps the hypothalamus also could be considered the “master gland.”

8. The functions of the adrenal gland hormones warrant extra attention. Both are important in regulating the body’s response to stress, both short term and long term. Presentation of the hormones of the adrenal medulla provides another opportunity to review the fight-orflight response previously discussed with the nervous system. In the adrenal cortex, the glucocorticoids are released to help maintain homeostasis during a long-term stress situation. Contrast and compare their functions. Also note to students that aldosterone and small amounts of sex hormones are produced in the cortex. Finally, point out that the anatomical two-layer cortex/medulla structure arrangement of the adrenal glands will be seen in other organs of the body as well, such as the kidneys, lymph nodes, and brain.

Key point: A discussion of the functions of the two layers of the adrenal glands helps to again emphasize the fine-tuned integration between the nervous and endocrine systems, as well as the body’s delicate balancing act in maintaining homeostasis. Emphasize how both layers secrete hormones that deal with stress, short term (catecholamines) and long term (glucocorticoids).

9. Discuss steroid use from exogenous sources such as anabolic steroid use and corticosteroid use for treatment of arthritis and inflammation.

Key point: Individuals who abuse anabolic steroids for athletic or appearance purposes are aging body tissues, such as the liver, at a much faster rate. Males may never again be able to endogenously produce a sperm count high enough to produce children even years after they stop taking exogenous testosterone. Also discuss how corticosteroid therapy is used for surfactant development in premature infants, but long-term treatment for in-

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flammation can lead to bone breakdown and immunosuppression. Steroid therapy, with its benefits and inherent dangers, opens the floor for a stimulating discussion.

10. Differentiate the functions of aldosterone and antidiuretic hormone.

Key point: Students often confuse these hormones. These two hormones should be revisited in the urinary system in more detail. For this chapter, the distinction of antidiuretic hormone function (depresses water excretion from the body) versus aldosterone secretion (promotes salt retention) should be made to the students. Both therefore affect fluid retention, but through different mechanisms.

11. Discuss type I and type II diabetes mellitus. Point out to students that although the result is the same, there are different causes of abnormally high blood sugar. Discuss treatment options.

Key point: Students usually are familiar with the condition of “diabetes” but often are unfamiliar with the differences between type I and type II. In type I diabetes, little or no insulin is produced because the islets of Langerhans are destroyed, whereas type II occurs when body cells become resistant to the effects of insulin and is often due to physical inactivity and obesity. Both types, if left untreated, can lead to a number of medical complications, including cardiovascular disease, neuropathies, and kidney, eye, and foot damage, to name a few. Discuss insulin replacement for type I, and the benefits of an active lifestyle for type II, for example. Point out that there are many undiagnosed diabetics in American society who are cutting years off their longevity by not getting appropriate treatment.

12. If asked what comes to mind when someone mentions “hormones,” students will usually say they think of estrogen (“female hormones”) and testosterone (“male hormones”).

This provides an excellent starting point for discussion of estrogen and testosterone and their roles in sexual development and reproduction. It also provides an opportunity to emphasize that the sex hormones represent only a few of the large number of important hormones in the body.

Key point: Discuss the roles of estrogen and testosterone in development and reproduction, as well as in aging, and how these hormones are found in both sexes.

13. Discuss circadian rhythms and the role of melatonin in this mechanism. Discuss also how cortisol levels increase and decrease in a circadian rhythm. Currently melatonin has gained popularity as a sleep aid. Discuss why it does not work to alleviate insomnia.

Key point: Melatonin plays an important role in regulating our sleep patterns and day– night cycle. Melatonin levels are usually lowered during sunlight hours. Jet lag and seasonal affective disorder (SAD) are thought to be due to dysregulation of melatonin. Cortisol levels also run in a circadian rhythm, inverse to that of melatonin. Melatonin administration can only shift the circadian rhythm, not resolve insomnia.

14. Discuss the importance of testosterone for gender determination in embryo development.

Explain the effects that can occur when too little testosterone or estrogen is present during development and puberty. Discuss androgen insensitivity syndrome.

Key point: Emphasize to students the large influence hormones have not only before birth but also for development of secondary sex characteristics, gamete production, and sex cell maturation.

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15. Explain the use of synthetic or animal hormones to treat conditions such as dwarfism (growth hormone) or diabetes mellitus (insulin).

Key point: Discuss with students the developments in medicine that provide hormone alternatives when endocrine glands do not function properly.

16. Discuss Graves’ disease as an example of how the endocrine and immune systems are interconnected.

Key point: This autoimmune disease, where the body creates antibodies that mimic thyroid stimulating hormone (TSH) to induce hyperthyroidism, is a good example of how the organ systems do not work in isolation and a disruption in one system can induce homeostatic imbalance in another system.

17. Describe hormone replacement therapy (HRT) for postmenopausal women, including both risks and benefits.

Key point: Many students are familiar with this therapy and can better understand its use once they know how the endocrine system works to maintain homeostasis. The risks that should be addressed include increased cancer, heart attacks, and strokes.

Classroom Demonstrations and Student Activities Classroom Demonstrations 1. Using a human torso model, indicate the body locations of the major endocrine organs.

2. Project a blank human figure onto a whiteboard/smartboard and name a tropic hormone.

Ask students to identify where the hormone is made and label the figure. Ask students the target tissue and draw an arrow to that tissue. Then ask students the function, which can be written adjacent to the arrow.

3. Obtain photographs of individuals with endocrine disorders—for example, individuals with exophthalmos and/or goiter resulting from Graves’ disease; persons with a distinctive “moon face” and “buffalo hump” from Cushing’s syndrome (as a result of adrenal hypersecretion); and gigantism, dwarfism, or acromegaly from growth hormone imbalances. Use these pictures to help students visualize physical manifestations of hyper- and hyposecretion disorders.

4. Bring in various hormones purchased from a health/nutrition store. Discuss the dangers of unregulated (not FDA-approved) use of these chemicals.

5. Have the students call out all of the responses they remember related to the fight-or-flight mechanism, contrasting it with the “rest and digest” mechanism, and write their responses on the board. Use this as a starting point to explain the roles of epinephrine and norepinephrine. Show students how both divisions affect the same organs in an antagonistic, counterbalancing fashion.

6. Bring in an epinephrine injector such as an EpiPen, and discuss how epinephrine is used in anaphylaxis. Emphasize the relationship between the immune and endocrine systems.

7. Have an EMT, paramedic, or ER physician come to class to talk about emergency treatment of patients with diabetes. Have them discuss treatment for hyperinsulinism as opposed to diabetic acidosis. ..

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8. Have a guest speaker from the American Diabetes Association come to class to talk about the impact of diabetes on lives and the lifestyle changes involved in managing the disease. Include in the discussion the differences between insulin-dependent diabetes mellitus (IDDM) and non-insulin-dependent (NIDDM) diabetes mellitus.

9. Bring in a sample of an early pregnancy testing kit to use in conjunction with discussion of human chorionic gonadotropin (hCG) and its production by the developing placenta.

10. Have an endocrinologist come to class to talk about common tests done to determine various endocrine disorders.

11. Show a video on leptin and obesity such as the one provided here: www.youtube.com/watch?v=lVl84cLFpgk Discuss neuroendocrine connections to obesity.

12. Discuss the potential dangers associated with xenoestrogens, such as bisphenol A (BPA).

Student Activities 1. Have students research phytoestrogens and discuss their findings on the beneficial and detrimental effects of these compounds.

2. Have the students research the current applications and experimental uses of recombinant human growth hormone, as well as growth hormones that are found in agricultural food production, and use their findings to promote a class discussion.

3. Have the students research the use of corticosteroids in such conditions as asthma, organ transplantation, and autoimmune disorders. Use this information to discuss the advantages and disadvantages of these drugs.

4. Have students investigate the pesticide DDT (banned in most countries) and its relationship to estrogen and present their research.

5. Have students create a chart with hormone name, where it is produced, mode of action (neural, hormonal, humoral), target tissue, type of hormone (protein, steroid), and any antagonistic hormones (insulin versus glucagon, for example). Alternatively, have a chart ready with some prefilled information and some blanks for the students to fill in.

6. Have students create a hormone receptor model using the resources found at www.pbs.org/wgbh/nova/education/activities/3313_03_nsn.html 7. Have students work in small groups to create either a video, animation, or live-action demonstration of steroidal and nonsteroidal pathways.

8. Create a matching game with cards or interlocking puzzle pieces and have students match hormones to their function. This can be an entire class activity or one done in smaller groups; students can form teams and compete based on how quickly they match.

Media See page 164 for a listing of media distributors.

1. Introduction to the Endocrine System (Khan Academy, 2011, www.khanacademy.org/science/health-and-medicine/advanced-endocrine-

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system/endocrine-system-introduction/v/intro-to-the-endocrine-system). Series of video tutorials on the endocrine system and its functions.

2. The Endocrine System Part 1: Glands and Hormones! (Crash Course: 11 min., www.pbslearningmedia.org/resource/endocrine-system-glands-hormones-crashcourse1023/endocrine-system-part-1-glands-hormones-crash-course-ap-23). Discusses hormones, their general functions, and their chemical composition, and provides a brief introduction to the HPA axis and the stress response.

3. The Endocrine System Part 2: Hormone Cascades (Crash Course: 10 min., www.pbslearningmedia.org/resource/endocrine-system-glands-hormones-crashcourse1024/endocrine-system-part-2-hormone-cascades-crash-course-ap-24). Discusses homeostasis and hormone cascades, with discussion of the HPT axis.

4. How Diabetes Affects Your Blood Sugar (Mayo Clinic: 3 min., www.mayoclinic.org/diseases-conditions/diabetes/multimedia/blood-sugar/vid20084642). A brief introduction of the effects of diabetes.

5. What Is Diabetes? (WebMD: 2 min., www.webmd.com/diabetes/video/video-what-istype-2-diabetes). A brief explanation of type II diabetes.

6. Trust, Morality—and Oxytocin?(TEDGlobal: 17 min., 2011, www.ted.com/talks/paul_zak_trust_morality_and_oxytocin). A neuroeconomist’s viewpoint on oxytocin.

7. Hormone Hell (FHS: 50 min., 1999, DVD, 3-year streaming webcast). From the Body Chemistry: Understanding Hormones series, this program examines the ways in which hormones affect different stages of life.

8. Endocrinology (TedEd: 22 min., 2016, ed.ted.com/on/zmrlnY9v). Video lesson on the endocrine system with an online quiz from TedEd resources.

9. The Sleep Famine: The Effects of Sleep Deprivation and Chronic Fatigue (FHS: 54 min., 2000, VHS, DVD). Discusses the societal impact of fatigue and the implications of timeshifting the circadian clock.

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CHAPTER

10

Blood

Chapter Summary Blood can be viewed as the body’s “river of life.” In the previous chapter, blood’s role in transporting hormones around the body was addressed. In this chapter, this key role of transport extends to nutrients, metabolic wastes, immune system cells and products, and, of course, oxygen.

Blood is classified as liquid connective tissue and is also known as vascular tissue. It is composed of two parts: (1) formed elements, which include living blood cells and cell fragments and (2) plasma, a nonliving matrix that contains soluble protein molecules that are visible during coagulation. The general physical characteristics of blood, including color, pH, and temperature, are presented, followed by a description of the plasma composition. The next section provides a detailed analysis of each of the formed elements (erythrocytes, leukocytes, and platelets). The primary function of erythrocytes as carriers of oxygen is explained, highlighting the role of hemoglobin in this capacity. General characteristics of leukocytes are described and then differentiated into granulocytes and agranulocytes, with the role of the cell types in each category presented. Platelets, also called thrombocytes for their clotting ability, are the last of the formed elements to be analyzed.

Hematopoiesis of the formed elements is presented in detail, including the role of the kidney hormone erythropoietin, together with the differentiation of hemocytoblasts into lymphoid and myeloid stem cells. The phases of hemostasis, or clot formation, are outlined next, followed by a summary of the homeostatic imbalances associated with hemostasis, which include undesirable clotting and bleeding disorders, such as thrombus formation or hemophilia.

The final section of the chapter usually piques the interest of students because it explains the concepts underlying blood typing and its impact on blood transfusions. The four ABO blood groups are presented first, along with a discussion of the phenomenon of agglutination, which elicits the symptoms of a transfusion reaction. Accompanying the presentation of Rh blood groups is an explanation of erythroblastosis fetalis, or hemolytic disease of the newborn.

Suggested Lecture Outline I. 10.1 Composition and Functions of Blood (pp. 331–340) A. 10.1a Components (p. 332) B. 10.1b Physical Characteristics and Volume (p. 332) C. 10.1c Plasma (p. 332) D. 10.1d Formed Elements (pp. 332–338) 1. Erythrocytes 2. Leukocytes 105 INSTRUCTOR GUIDE FOR ESSENTIALS OF HUMAN ANATOMY & PHYSIOLOGY, 13e

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3. Platelets E. 10.1e Hematopoiesis (Blood Cell Formation) (pp. 338– 340) 1. Formation of Red Blood Cells 2. Formation of White Blood Cells and Platelets

II. 10.2 Hemostasis (pp. 340–343) A. 10.2a Phases of Hemostasis (pp. 341–342) B. 10.2b Disorders of Hemostasis (pp. 342–343) 1. Undesirable Clotting 2. Bleeding Disorders

III. 10.3 Blood Groups and Transfusions (pp. 343–346) A. 10.3a Human Blood Groups (pp. 343–344) B. 10.3b Blood Typing (pp. 344–346)

IV. 10.4 Developmental Aspects of Blood (p. 346) Note: For a list of Key Terms for this chapter, please go to Mastering A&P > Study Area > Additional Study Tools > Key Terms > Chapter 10.

Learning Objectives 10-1 Describe the composition and volume of whole blood.

10-2 Describe the composition of plasma, and discuss its importance in the body.

TEACHING TIP For blood typing, understanding which antigens on the blood cell surface go with which antibodies in the bloodstream is difficult for students. For each blood type, draw the antigen(s) that is/are present on the cell surface of a blood cell, and draw the antibodies that would be circulating in the bloodstream. It is helpful to designate specific shapes for each antigen, for example, a triangle for A, a circle for B, and so on, with complementary-shaped antibodies for each respective antigen. Comprehension of the antigen–antibody relationships will also aid in the understanding of crossmatching for transfusions.

For an additional genetics spin, a diagram illustrating, for example, how an individual with B blood type could be BB or BO also can be drawn.

10-3 List the cell types making up the formed elements, and describe the major functions of each type.

10-4 Define anemia, polycythemia, leukopenia, and leukocytosis, and list possible causes for each condition.

10-5 Explain the role of the hemocytoblast.

10-6 Describe the blood-clotting process.

10-7 Name some factors that may inhibit or enhance the blood-clotting process.

10-8 Describe the ABO and Rh blood groups.

10-9 Explain the basis for a transfusion reaction.

10-10 Explain the basis of physiologic jaundice seen in some newborn babies.

MEDIA TIP What is Inside of Blood?

(Khan Academy: 12 min., 2012, www.khanacademy.org/scie nce/health-andmedicine/lab-values/v/whats-inside-ofblood?v=5MOn8X-tyFw).

Explains the components of blood.

10-11 Indicate blood disorders that increase in frequency in the aged.

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Resources for Teaching Online Discussion Board Topic: Homeostatic Imbalance—Leukemia In the textbook on page 336, the Homeostatic Imbalance section explains that leukemia is a condition in which the bone marrow becomes cancerous and excessive numbers of nonfunctional white blood cells (WBCs) are created and spread throughout the body, leading to immunosuppression. Engage your students by using the following discussion questions in lecture or by posting them to the discussion board on your course management system.

Discussion Questions 1. What is the basis of classification for the various forms of leukemia?

2. What is the most common form of leukemia in children? In adults? What are some symptoms?

3. What are current treatment options for leukemia?

Potential Student Responses 1. Which cells become dysfunctional: lymphoid stem cells or myeloid stem cells? Rate of progression: acute: fast; chronic: slow.

2. Acute lymphoblastic/lymphocytic leukemia in children. For adults, the most common leukemia is chronic lymphocytic leukemia. General symptoms for both types include fatigue, fevers, frequent infections, swollen lymph nodes, petechiae, pallor, easy bruising, bone/joint pain.

3. Combined drug chemotherapy (e.g., tyrosine kinase inhibitors, histone deacetylase inhibitors, hypomethylating or demethylating agents, nucleosides, immunomodulators, monoclonal antibodies, and proteasome inhibitors) with possible concurrent radiation therapy. There are also immunotherapies that focus on T-cell stimulation through chimeric antigen receptor-T (CART) cells, gene therapies, and bone marrow, stem cell, and cord blood transplantation therapies.

Investigate Online Take learning a step further by searching for relevant research articles on the Web. Visit science websites, such as those listed below, and begin by searching for key terms such as lymphoid leukemia, acute lymphoblastic leukemia, chronic lymphocytic leukemia, hairy cell leukemia, adult T-cell leukemia/lymphoma, myeloid leukemia, acute myeloid leukemia, and chronic myelogenous leukemia and see how what you’re learning in the course applies to science and medicine today. www.sciencedaily.com www.scientificamerican.com www.the-scientist.com www.ncbi.nlm.nih.gov/pubmed www.cancer.gov/types/leukemia/research

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Study Tips Direct students to the Study Tips feature located in the front of the book.

Mastering A&P Numerous items from Mastering A&P can be demonstrated in class, assigned as homework, or encouraged as study materials. These include practice tests and quizzes, animations and videos, Interactive Physiology (IP), Dynamic Study Modules, Audio Journeys, Practice Anatomy Lab (PAL), PhysioEx, flashcards, glossary, key terms, and more.

PhysioEx10.0 The following sections of PhysioEx10.0 are relevant to this chapter:

Videos of PhysioEx Lab Experiments: Blood Typing

Exercise 11: Blood Analysis

Practice Anatomy Lab (PAL)3.1: Including Mobile Flashcards The following section of PAL3.1 is relevant to this chapter:

Histology > Cardiovascular System > Blood smear slides

Additional Study Tools The following Additional Study Tool is relevant to this chapter:

Focus On Careers > Phlebotomy Technician

Lecture Hints 1. Discuss derivation of blood cell nomenclature, such as erythrocyte, leukocyte, basophil, and eosinophil.

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Key point: The names of the blood cells are easy to remember by learning the etymology. Red blood cells and white blood cells are straightforward (erythro = red, leuko = white, cyte = cell) and a good introduction. Then cells such as the basophil and eosinophil can be explored. These cells are named from the staining dyes used to visualize them. Basophils are visualized with a blue basic dye, while eosinophils are stained with eosin, an acidic dye that is pink in color.

2. Discuss hematocrit and hemoglobin lab tests and their significance in the diagnosis of the more common types of anemia.

Key point: Students who have donated blood may have had their hematocrit measured.

Hematocrit tests are used to diagnose types of anemia caused by low numbers of red blood cells (RBCs), whereas hemoglobin tests are used to diagnose types of anemia caused by deficient hemoglobin concentration in the blood.

3. Describe a typical blood panel test for a physical or in the emergency room. Students are amazed at what can be diagnosed in the blood: from bacterial presence (blood culture) to pancreatic function (amylase levels), to potential cancer genes, such as BRCA1 or BRCA2.

4. Explain sickle-cell anemia and its natural selection benefit in protecting against malaria.

Briefly explain the difference between homozygous recessive sickle-cell anemia and heterozygous sickle-cell trait.

Key point: Discussion of sickle-cell anemia provides an opportunity to show how, through genetic mutation of just one amino acid, the human body can and does adapt to environmental influences over generations.

5. Discuss the use of low doses of aspirin to reduce the risk of heart disease or stroke.

Key point: These medications can decrease the probability of thrombus formation in patients who have suffered previously from heart disease. There is evidence, however, that prophylactic treatment in normal individuals can be potentially detrimental, leading to such issues as gastric bleeding.

6. Students are quite interested in the hereditary condition of hemophilia and are particularly fascinated by its presence in the British, Russian, German (Prussian), and Spanish royal lineages. Make hemophilia an element of your discussion of coagulation events by noting which of the several possible clotting factors are frequently lacking in people with hemophilia.

Key point: Hereditary bleeding disorders result from deficiency of any of the factors needed for clotting, but missing factor VIII or factor IX, which are both an X-linked recessive trait, results in the two principal types of hemophilia.

7. Discuss lymphoid and myeloid stem cells and what cells they normally generate. Use leukemia as an example to discuss what happens when either type of stem cell turns cancerous, and the consequences.

Key point: Leukemia is a cancer that students have heard of, and discussing how the cancerous stem cell can impact the immune system differentially between the lymphoid and myeloid lines will help in understanding the relationship between this chapter and the immune system chapter.

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8. Describe the process of bone marrow transplantation for treatment in leukemia patients.

Key point: Point out to students that matches between donor and recipient are more precise for bone marrow transplants compared to blood transfusions. Explain the problems associated with rejection of the donor’s bone marrow in patients who have leukemia and already have a suppressed immune system.

9. Explain the difference between the lab tests for prothrombin time (PT) and partial thromboplastin time (PTT) and their uses in determining the causes of unexplained bleeding.

Key point: Bleeding disorders and coagulation problems resulting from medication can cause imbalance at various stages in the coagulation process. Lab values out of the normal range for PT or PTT are each significant for specific conditions.

10. Explain to students that the liver is the source of most plasma proteins, including albumin and the clotting proteins.

Key point: Liver disease, a homeostatic imbalance, can lead to edema and bleeding disorders.

11. Discuss fetal and adult hemoglobin differences. Discuss why fetal hemoglobin is more effective in binding oxygen, and why this is necessary.

Key point: The fetus obtains blood from the mother through the placenta (rather than the lungs); therefore, fetal hemoglobin must have a higher affinity for oxygen than adult hemoglobin. Additionally, this ties in the concept introduced in the circulatory system chapter about mixed oxygenated-deoxygenated blood in the fetal heart, where fetal hemoglobin again plays a significant role.

12. Discuss why carbon monoxide inhalation can lead to death. Explain that hemoglobin has a higher affinity for carbon monoxide (CO) than for oxygen. Therefore, if CO is present, hemoglobin will preferentially bind to it, rather than oxygen.

Key point: Students are usually surprised that hemoglobin would preferentially bind to something other than oxygen and that hemoglobin does not want to release CO once bound. This hemoglobin binding example connects the concepts introduced in the basic chemistry chapter.

13. Discuss why having enough iron in the diet is important. Discuss what foods contain high amounts of iron.

Key point: This emphasizes the importance of iron in the structure of hemoglobin, describes easy-to-understand health implications with anemia and hemochromatosis, and shows why iron is important in a healthy diet.

14. Discuss polycythemia and the extreme example of blood doping. Show students the Lance Armstrong interview with Oprah Winfrey where he admits to blood doping during all of his Tour de France victories. (2013, 2min., www.youtube.com/watch?v=N_0PSZ59Aws).

Key point: This concept will allow students to understand the mechanisms of erythropoietin action. Discussion can begin with noting that athletes may train in high altitudes to increase oxygen-carrying capacity. Describe the extreme measure of withdrawing and replacing blood in conjunction with synthetic erythropoietin administration, which can ..

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increase endurance but also blood viscosity. This can lead to hypertension, thrombus development, strokes, and even death.

15. Discuss what it means to be a universal donor and universal recipient for blood donation.

Key point: Although it is a difficult topic, students enjoy learning about blood typing because it is a relevant one. Moreover, discussion of this topic allows for evaluation of student understanding of this concept. Be sure to discuss blood typing within the context of both the ABO and Rh blood groups.

16. Discuss the different components of blood that can be donated. Indicate how often each type occurs.

Key point: Many students donate blood and are often interested in not only the difference between types of donation but also the conditions in which people could receive donated blood.

17. Discuss Rh incompatibilities and erythroblastosis fetalis. Explain the treatment protocol associated with RhoGAM to prevent this occurrence in an Rh− woman pregnant with an Rh+ fetus.

Key point: Treatment protocols have made erythroblastosis fetalis far less common in the United States than in decades past, but it continues to be of global significance as a health issue for women of child-bearing age. Emphasize why the first exposure of an Rh– woman to an Rh+ fetus is okay but subsequent exposures are destructive.

Classroom Demonstrations and Student Activities Classroom Demonstrations 1. Using micrographs or a microscope that is connected to a TV or computer monitor, show the various blood cell types and point out characteristics.

2. Draw Punnett squares for ABO and Rh blood typing so that students can understand the simple genetic basis for how, for example, parents who are A and B blood types can have an O type baby (AOxBO; 25% chance).

3. On the board, outline the constituents of blood, including plasma and all the formed elements, as well as the percentages of each that are normally found in healthy blood. Play a video on centrifugal blood separation to allow students to visualize the areas of separation between the erythrocytes, white blood cells and platelets, and plasma.

4. Show examples of stained leukocytes, explaining how Wright, Leishman, and other stains are used to differentiate between the various granulocytes and agranulocytes.

5. Display equipment used to perform hematocrit, sedimentation rate, and blood cell counts.

Describe how these tests are conducted and what information they yield, then run a hematocrit so students can see the difference in the volume of plasma and formed elements.

6. Set up prepared slides of pathologies such as sickle-cell anemia, leukemia, erythroblastosis fetalis, and iron-deficiency anemia. Ask students to discuss how these blood smears differ from blood smears from healthy individuals.

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7. Invite a phlebotomist to the class to talk about the procedures and protocols he or she follows. Have the phlebotomist explain the different types of blood tubes used for blood collection. The phlebotomist could also explain the different types of needles and the various sites used for drawing blood in children and adults. Have the speaker explain the difficulties in drawing blood when the patient is obese or dehydrated, as well as the methods he or she uses during those situations.

8. Have a representative from the local medical center or blood bank talk to the class about blood donation: the requirements, the procedure, and how the donated blood is used.

9. Have a representative from bone marrow and/or cord blood donation registries to class to discuss the requirements and procedures they follow, how the donated stem cells can be used, and how the process differs from regular blood donation.

10. To stimulate discussion of how modern medicine can utilize old folk remedies, have students watch a video on the therapeutic uses of leeches: www.youtube.com/watch?v=cKUAroimQrk

Student Activities 1. Use WARD’s Simulated Blood Typing “Whodunit” Lab Activity. This is a fun, easy-touse activity in which students become detectives and use blood-typing techniques to solve a make-believe crime. Alternatively, use Carolina’s ABO-Rh Blood Typing with Synthetic Blood Kit. 2. Have students play the Red Cross Blood Typing game (www.redcrossblood.org/donating-blood/donor-zone/games/blood-type).

3. Show students unlabeled slides of various blood cells. Ask students to name the cells and the specific physical characteristics that lead them to their conclusion.

4. Have students research diseases that are transmitted via blood. Discuss why many of these diseases are increasing in incidence and explain why careful handling of blood in the clinical agency is vitally important. Present information on standard precautions as recommended by the Centers for Disease Control and Prevention.

5. Collect data from the class about their own blood types. Compare these data to expected frequency.

6. Create a matching game with cards or interlocking puzzle pieces and have students match various blood disorders with their signs and symptoms.

7. Have students research the use of synthetic erythropoietin in cancer therapy.

8. Create a Jeopardy-style game where questions can be answered about various characteristics and functions of the formed elements, and the composition of plasma.

9. Have some volunteers from class come to the front of the class with puzzle pieces. Use them to demonstrate how a specific antigen and its specific antibody fit together perfectly. Do this for each of the ABO blood groups so students are able to understand the relationship and specificity of each antigen-antibody pair. Extend the exercise to demonstrate to students which antigen is on the cell surface, and which antibodies are circulating in the host. Finally, these students can also simulate a transfusion reaction.

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Media See page 164 for a listing of media resources.

1. Bad Blood (FHS: 50 min., 1996, VHS, DVD, 3-year streaming webcast). Explores the ancient fear associated with inherited conditions, including an examination of the royal link to hemophilia.

2. Bleeding and Coagulation (FHS: 31 min., 2000, VHS, DVD, 3-year streaming webcast).

Scrutinizes the body’s mechanism of coagulation through the use of case studies.

3. Blood Part 1: True Blood (Crash Course: 10 min., 2015, ca.pbslearningmedia.org/resource/blood-platelets-plasma-video-crashcourse-1029/bloodpart-1-true-blood-crash-course-ap-29). Brief overview of blood.

4. Blood Part 2: There Will be Blood (Crash Course: 10 min., 2015, ca.pbslearningmedia.org/resource/blood-oxygen-hemoglobin-video-crashcourse1030/blood-part-2-there-will-be-blood-crash-course-ap-30). Explains red blood cell characteristics and stimulation, including the dangerous practice of blood doping.

5. How the Heart Actually Pumps Blood (TedEd: 5 min., 2016, ed.ted.com/lessons/howthe-heart-actually-pumps-blood-edmond-hui#review). Brief overview of pumping mechanism of heart with accompanying self-quiz.

6. Mechanisms of Defense: Accident (FHS: 28 min., 1984, VHS, DVD, 3-year streaming webcast). From the award-winning Living Body series, this program follows the sequence of events of body reparation following an accident. Includes defensive reactions such as blood clotting.

7. Sickle Cell Anemia (FHS: 30 min., 2001, VHS, DVD, 3-year streaming webcast). Answers frequently asked questions about the causes of sickle-cell anemia and its treatment.

8. Blood Detectives (American Society of Hematology: 60 min., 2008, DVD). An introduction to blood and its disorders.

9. Red Gold: The Epic Story of Blood (PBS, 240 min., 2002, DVD). This program addresses the impact of human blood on various aspects of society, medicine, religion, and popular culture.

10. Hematologic System Introduction (Khan Academy: 2016, www.khanacademy.org/science/health-and-medicine/advanced-hematologicsystem#hematologic-system-introduction). Various multimedia modules on blood cells, blood typing, and coagulation.

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CHAPTER

11

The Cardiovascular System

Chapter Summary There is a public health focus on the cardiovascular system, because heart disease continues to be the leading cause of mortality in the United States. Nevertheless, the importance of the cardiovascular system cannot be overstated. This chapter will focus students on the complexity of the system and its significance to all other body systems, as it is the transport system to and from the organs.

This chapter begins with fundamental information about the heart by first discussing anatomy and then moving on to the more complex physiology. The section on anatomy discusses the layers of the heart, as well as its chambers, valves, and the vessels through which blood moves in and out in a committed pathway. A section on cardiac circulation explains the way the heart itself is supplied with oxygen-rich blood.

The structural and mechanical characteristics of the heart are followed by coverage of its unique intrinsic electrical activity. The conduction system is outlined, and relevant homeostatic imbalances are discussed. The corresponding cardiac cycle, which can be visualized on an electrocardiogram, is a challenging concept for students. However, once the cardiac cycle is mastered, students will have a better understanding of the well-coordinated mechanisms underlying how the chambers, valves, and large blood vessels shuttle the blood through the heart to the body and back.

Discussion of cardiac output is an effective segue to the blood vessels. Arteries, veins, and capillaries are compared for their structural and physiological similarities, as well as their differences. Names of the major vessels are given, as the route of blood is traced from its point of exit from the heart through the aorta to all parts of the body and back to the heart via the superior and inferior venae cavae. A look into the various mechanisms involved in blood pressure precedes a discussion of the special circulatory routes that supply the brain, liver, and developing fetus. Finally, the developmental aspects of circulation are considered.

Suggested Lecture Outline I. 11.1 The Heart (pp. 352–365) A. 11.1a Anatomy of the Heart (pp. 352–355) 1. Size, Location, and Orientation 2. Coverings and Walls of the Heart B. 11.1b Chambers and Associated Great Vessels (pp. 353–356) C. 11.1c Heart Valves (pp. 356–358) 1. Cardiac Circulation D. 11.1d Physiology of the Heart (pp. 359–365) 1. Intrinsic Conduction System of the Heart: Setting the Basic Rhythm ..

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2. Cardiac Cycle and Heart Sounds 3. Cardiac Output a. Regulation of Stroke Volume b. Factors Modifying Basic Heart Rate

II. 11.2 Blood Vessels (pp. 365–383) A. 11.2a Microscopic Anatomy of Blood Vessels (pp. 366– 368) 1. Tunics 2. Structural Differences in Arteries, Veins, and Capillaries B. 11.2b Gross Anatomy of Blood Vessels (pp. 369–3742) 1. Major Arteries of the Systemic Circulation a. Arterial Branches of the Ascending Aorta b. Arterial Branches of the Aortic Arch c. Arterial Branches of the Thoracic Aorta d. Arterial Branches of the Abdominal Aorta 2. Major Veins of the Systemic Circulation a. Veins Draining into the Superior Vena Cava b. Veins Draining into the Inferior Vena Cava 3. Special Circulations a. Arterial Supply of the Brain and the Circle of Willis b. Hepatic Portal Circulation C. 11.2c Physiology of Circulation (pp. 374–383) 1. Arterial Pulse 2. Blood Pressure a. Blood Pressure Gradient b. Measuring Blood Pressure c. Effects of Various Factors on Blood Pressure i. Neural Factors: The Autonomic Nervous System ii. Renal Factors: The Kidneys iii. Temperature iv. Chemicals v. Diet d. Variations in Blood Pressure 3. Capillary Exchange of Gases and Nutrients 4. Fluid Movements at Capillary Beds

TEACHING TIP The cardiac cycle is a challenging concept for the students. It is helpful to juxtapose a normal electrocardiogram tracing with the diagram of the cardiac cycle events (Figure 11.8). Discuss how the intrinsic conduction pathway that is recorded by the ECG stimulates blood movement through the heart by stimulating contraction of the atria and ventricles as the electrical impulse set by the SA node travels through the heart tissue. After students understand this relationship, also relate the heart sounds to the valves that are being closed during chamber contraction. Relate this discussion to the direction of blood flow, and the oxygenation status of the blood. The interrelationship of these events initially must be explained and diagrammed by the instructor, only after which the student can reinforce the knowledge learned in class by reading the section in the text.

MEDIA TIP Human Body: The Cardiovascular System (AMB: 29 min., 2010). Examines the anatomy and physiology of the cardiovascular system with the help of 3-D graphics, medical imaging, and cadaver specimens.

III. 11.3 Developmental Aspects of the Cardiovascular System (pp. 383–385) Note: For a list of Key Terms for this chapter, please go to Mastering A&P > Study Area > Additional Study Tools > Key Terms > Chapter 11.

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Learning Objectives 11-1 Describe the location of the heart in the body, and identify its major anatomical areas on an appropriate model or diagram.

11-2 Trace the pathway of blood through the heart.

11-3 Compare the pulmonary and systemic circuits.

11-4 Explain the operation of the heart valves.

11-5 Name the functional blood supply of the heart.

11-6 Name the elements of the intrinsic conduction system of the heart, and describe the pathway of impulses through this system.

11-7 Explain what information can be gained from an electrocardiogram.

11-8 Define systole, diastole, stroke volume, cardiac cycle, heart sounds, and heart murmur.

11-9 Describe the effect of each of the following on heart rate: stimulation by the vagus nerve, exercise, epinephrine, and various ions.

11-10 Compare and contrast the structure and function of arteries, veins, and capillaries.

11-11 Identify the body’s major arteries and veins, and name the body region supplied by each.

11-12 Discuss the unique features of the arterial circulation of the brain and hepatic portal circulation.

11-13 Define pulse, and name several pulse points.

11-14 Define blood pressure, and list factors affecting and/or determining blood pressure.

11-15 Define hypertension and atherosclerosis, and describe possible health consequences of these conditions.

11-16 Describe the exchanges that occur across capillary walls.

11-17 Briefly describe the development of the cardiovascular system.

11-18 Name the fetal vascular modifications, or “fetal shunts,” and describe their function before birth.

11-19 Describe changes in the cardiovascular system that occur with aging, and list several factors that help maintain cardiovascular health.

Resources for Teaching Online Discussion Board Topic: Homeostatic Imbalance—Pericarditis In the textbook on page 353, the Homeostatic Imbalance section explains that pericarditis is an inflammation of the pericardium, with resulting serous fluid loss that increases friction between the pericardial layers. Engage your students by using the following discussion questions in lecture or by posting them to the discussion board on your course management system.

Discussion Questions 1. What are the potential causes/risk factors for pericarditis?

2. What are some imaging tools used to diagnose pericarditis?

3. What is the clinical presentation of pericarditis?

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Potential Student Responses 1. Although the cause of pericarditis is not always known, viral infection precedes pericarditis, although there are also cases of bacterial, parasitic, and fungal pericarditis. Radiation therapy, metastatic disease, kidney failure, and having certain autoimmune diseases, such as lupus or rheumatoid arthritis, may lead to a higher susceptibility for pericarditis.

Also, having heart surgery or a heart attack is a risk factor. Trauma to the chest is also a risk factor. This condition occurs more frequently in men between the ages of 20 and 50; prior respiratory infection appears to increase susceptibility.

2. Some common diagnostic imaging tools for pericarditis include CT, MRI, or X-ray of the chest, as well as an echocardiogram (ECG).

3. Symptoms include sharp pain in the center or left side of the chest that may radiate to the neck, shoulder, back, or abdomen, and which is alleviated when the patient stands up; shortness of breath when lying down; low fever; fatigue; dry cough; and abdominal or leg swelling. Signs include a “pericardial rub” sound when the two layers rub against each other, enlarged heart due to accumulation of pericardial fluid, and thickening of the pericardial wall.

4. For acute cases, drug treatments include nonsteroidal anti-inflammatory drugs (ibuprofen or aspirin), antibiotics for bacterial pericarditis, and antifungals for fungal pericarditis.

For chronic pericarditis, drug treatments include ibuprofen with another antiinflammatory drug, either colchicine and/or prednisone; in some cases, surgical treatment is appropriate.

Investigate Online Take learning a step further by searching for relevant research articles on the web. Visit science websites, such as those listed below, and begin by searching for key terms such pericarditis, bacterial pericarditis, fungal pericarditis, parasitic pericarditis, acute pericarditis, recurrent pericarditis, chronic pericarditis, familial Mediterranean fever (FMF), uremic pericarditis, Dressler’s syndrome, pericardiectomy, pericardiocentesis, and pericardial window and see how what you’re learning in the course applies to science and medicine today. www.sciencedaily.com www.scientificamerican.com www.the-scientist.com www.ncbi.nlm.nih.gov/pubmed

Study Tips Direct students to the Study Tips feature located in the front of the book.

Mastering A&P Numerous items from Mastering A&P can be demonstrated in class, assigned as homework, or encouraged as study materials. These include practice tests and quizzes, animations and videos, Interactive Physiology (IP), Dynamic Study Modules, Audio Journeys, Practice Anatomy Lab (PAL), PhysioEx, flashcards, glossary, key terms, and more.

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Interactive Physiology (IP) The following sections of Interactive Physiology are relevant to this chapter: Cardiovascular System IP2: Electrical Activity of the Heart IP2: Cardiac Cycle IP2: Cardiac Output IP2: Factors Affecting Blood Pressure IP Animation: Pathway of Blood through the Heart IP Animation: Action Potentials in Autorhythmic Cells IP Animation: Intrinsic Conduction System of the Heart IP Animation: Cardiac Cycle IP Animation: Regulation of Cardiac Output IP Animation: Arterial Baroreceptor Reflex IP Animation: Capillary Pressure and Capillary Exchange

PhysioEx10.0 The following sections of PhysioEx10.0 are relevant to this chapter:

Videos of PhysioEx Lab Experiments: Cardiovascular Physiology

Exercise 5: Cardiovascular Dynamics

Exercise 6: Cardiovascular Physiology

Animations and Videos The following animations and videos are relevant to this chapter:

Bone and Dissection Videos > Cow and Sheep Dissection > Sheep Heart: Right Side; Sheep Heart: Frontal Section; Sheep Heart: External

Bone and Dissection Videos > Cat Dissection > Blood Vessels of the Thorax

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Bone and Dissection Videos > Fetal Pig Dissection > Heart and Blood Vessels of the Abdomen; Heart and Blood Vessels of the Thorax

Practice Anatomy Lab (PAL)3.1: Including Mobile Flashcards The following sections of PAL3.1 are relevant to this chapter:

Human Cadaver > Cardiovascular System > Heart; Blood Vessels

Anatomical Models > Cardiovascular System > Heart; Veins; Arteries

Histology > Cardiovascular System

Cat > Cardiovascular System Fetal Pig > Cardiovascular System

Lecture Hints 1. Descriptively present the cardiovascular system as the great transportation system of the body, similar to a mail delivery system, which not only carries the oxygen and carbon dioxide but also delivers nutrients, removes toxic wastes, conveys heat, and transports the myriad hormones essential to all regulatory functions.

Key point: Drawing an analogy between the cardiovascular system and a mail delivery system helps students conceptualize the transport function of the heart, blood vessels, and blood.

2. Although the left side of the heart generates more pressure than the right side, approximately the same volume of blood is ejected from each side per beat. First, address why the left side needs to generate more pressure. Then, ask students to think about what would happen if the same volume of blood was not ejected. Follow up with a discussion on congestive heart failure.

Key point: The left ventricle needs to pump out blood to the rest of the body, while the right ventricle needs only to pump blood to the lungs. In congestive heart failure (CHF), blood pumped to the lungs by the right ventricle does not keep pace with blood pumped around the system by the left ventricle. Fluid builds up in the lungs, leading to the predominant symptom of CHF, which is breathing difficulty.

3. Discuss takotsubo cardiomyopathy (broken heart syndrome), where the left ventricle function is affected.

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Key point: Students may be surprised to learn that there are physiological signs that can appear temporarily after “heartbreak,” such as ECG abnormalities that mimic those of a heart attack, and ballooning of the left ventricle; however, there is no coronary artery obstruction. This is a direct demonstration of the effects of stress (in this case, thought to be due to epinephrine secretion) on health status.

4. Compare the body’s self-regulating pacemaker, the SA node, to an artificial pacemaker in function and performance. Describe the 1 million or more times each week that the heart’s pacemaker fires and causes it to pump blood around the system and back again to the heart.

Key point: Students are usually quite surprised to learn that humans have a built-in “electrical” pacemaker consisting of specialized cells that are autorhythmic and can generate an electrical impulse.

5. Stress that the only function of the valves of the heart is to ensure the one-way flow of blood. Explore with the students the consequences of incompetent or stenotic valves.

Key point: This provides an opportunity to differentiate between the various types of murmurs and their etiology.

6. Discuss the chordae tendinae, or “heartstrings,” and explain how their function is similar to how a drawstring bag pulls shut. Note how the structure is designed to keep the heart valves from turning inside-out under extreme pressure.

Key point: The reference to something “tugging at the heartstrings” gives students a concrete example of the way in which anatomy, particularly of the heart, has an established place in our language and literature.

7. Explain how the atrioventricular (AV) and semilunar valves function differently to prevent backflow of blood. Emphasize that during ventricular systole, the AV valves prevent backflow of blood by acting like a closed one-way door. The pulmonary and aortic semilunar valves are named for the structures they separate from their respective ventricles, the pulmonary trunk, and the aorta. The semilunar valves function as an impermeable but flexible net to catch backflow of blood from the major vessels and prevent blood return to the ventricles after ventricular systole.

Key point: Explaining how valves function will help students solidify their understanding of the locations of the valves within the heart and will lend insight into the complementarity of structure and function.

8. Discuss the heart sounds and how the two AV valves close together (lub) and how the two semilunar valves close together (dub).

Key point: In learning about the heart, there is emphasis on the pathway of the blood in the systemic and pulmonary circulations, where deoxygenated blood is taken through the right side of the heart to the lungs, and then oxygenated blood returns through the left side. However, it is important to emphasize to students that while blood is in the heart it is pumped through both atria at the same time (atrial systole) and then both ventricles at the same time (ventricular systole), stimulated by the intrinsic conduction system pathway.

9. Outline the remarkable engineering involved in the design of the blood vessels, which allows them to absorb the pressure emitted from the heart with each beat and to return blood back to the heart, usually on an uphill course against the constant pull of gravity. ..

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Key point: In differentiating between arteries, veins, and capillaries, emphasize that the structure of each type of vessel is related to the differing amounts of pressure they must each absorb from the heart, as well as their respective roles in blood transport.

10. A basic misconception students have is that arteries carry oxygenated blood and veins carry deoxygenated blood. While this is usually true in the systemic circulation, the pulmonary circuit is a notable exception. Remind students that arteries carry blood away from the heart and veins carry blood toward the heart.

Key point: The pulmonary arteries carry deoxygenated blood from the right side of the heart to the lungs, and the pulmonary veins return oxygenated blood to the left side of the heart.

11. Another misconception that some students have is that deoxygenated blood is blue. Discuss that although veins are coded blue in textbooks and diagrams, and may look blue under the skin, when blood is drawn into a sterile, vacuum container, it is still red.

Key point: Explain that due to hemoglobin structural changes, the blood is a darker red when deoxygenated, whereas oxygenated blood is a brighter red. This provides an opportunity to connect information taught in the previous chapter. Students may have been mistakenly taught that venous blood changes color to red when it hits air. This misconception must be explained correctly.

12. Veins are more superficial and are occluded when a phlebotomist applies a tourniquet that enables veins to rise toward the skin surface as blood is still being pumped distally through arteries running underneath the tourniquet.

Key point: Veins are low-pressure vessels and need less strength, support, and elasticity than the arteries.

13. In discussing fetal circulation, point out that all fetuses have a “hole in their heart,” and in fact two holes, which allow circulation to be routed around the uninflated lungs. Explain the fact that if these holes don’t close at or shortly after birth, then surgical closure is required, usually to correct a patent ductus arteriosus (PDA).

Key point: Again, this is an example of a linguistic reference that has an actual anatomic basis, which students find fascinating. Point out to students that blood is routed around the lungs, because the placenta is the site of gas exchange in the fetus.

14. Discuss the blood supply to the heart itself, pointing out that despite the fact that blood fills all the chambers of the heart, the heart cannot nourish itself from the inside. Explain coronary artery disease (CAD) and its common sequelae, the coronary artery bypass graft (known as CABG and pronounced “cabbage”).

Key point: It is important for students to recognize that the heart must be infiltrated with its own vascular supply in order to receive the oxygen and nutrients necessary for its survival. Any blockage in the vascular flow will lead to tissue damage, resulting in a myocardial infarction or “heart attack.”

15. Differentiate between atherosclerosis and arteriosclerosis, pointing out that athero means “yellow, fatty plaque,” and discuss the role of cholesterol in its development. Show a video of atherosclerosis (2009, 3 min., www.youtube.com/watch?v=OHE1ig4k64M).

Key point: Atherosclerosis is a type of arteriosclerosis. Atherosclerosis is a buildup of fatty plaques on the interior of artery walls; arteriosclerosis is the hardening of the artery walls.

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16. Describe the various methods that can be used to treat atherosclerosis (e.g., stents, angioplasty).

Key point: Students are generally familiar with the concept of blocked blood vessels but are often unaware of treatments other than bypass surgery.

17. Discuss HDLs, LDLs, and VLDLs. Key point: The HDLs deliver cholesterol from the peripheral tissues to the liver. The LDLs transport cholesterol to the peripheral tissues. The VLDLs are the carriers of triglycerides to the peripheral tissue during fasting periods. HDLs are considered to be the “good” cholesterol, versus both LDLs and VLDLs, which are considered to be “bad” cholesterol.

18. Discuss smoking and its cardiovascular implications, including arteriovascular insufficiency, ischemia, intermittent claudication with concomitant leg pain and cramps, thrombus formation, and impotence.

Key point: The impact of smoking on the cardiovascular system is so significant that it is important to incorporate a discussion of the smoking-related disorders into the class presentation.

19. Present information on deep vein thrombi (DVTs) and their incidence related to bed rest and/or a sedentary lifestyle. Explain their connection to long-distance travel, birth control pills, and genetics. Point out the irony that the treatment for DVTs includes bed rest along with anticoagulant medication.

Key point: This discussion helps students gain perspective on potential serious homeostatic imbalances of the venous system and their causes.

20. Discuss the correlation of group A streptococcal infections such as “strep throat” to rheumatic fever and rheumatic heart disease, which can lead to mitral valve damage.

Key point: Students are usually familiar with the illness described as “strep throat” but often are unaware of its serious ramifications.

21. Explain the etiology and pathology associated with hypertension, along with methods of prevention and treatment options.

Key point: Because hypertension is one of the major risk factors in coronary artery disease, stroke, congestive heart failure, and kidney failure, presentation of the causative factors and current thinking on prevention and treatment are important concepts for students to understand. Excessive salt in the diet retains more fluid within the vessels and thus increases blood pressure internally, as compared to external stressors that increase blood pressure externally.

22. Explain that the intrinsic electrical conduction can be picked up by ECG electrodes placed anywhere on the external skin surface.

Key point: Electrical activity goes from the body to the machine, and heart paddles placed on an emergency patient are designed to stop the heart and hopefully enable normal autorhythmicity to take over. Explain that a rescuer would not want to give a patient just pulled out of a swimming pool several hundred joules of energy if the deck is not dry.

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23. Differentiate between myocardial infarction, stroke, pulmonary embolism, and thrombi.

Key point: Students often do not realize that these terms can all be related to one another because they refer to blockage of blood vessels in different parts of the body.

24. Explain the difference between an aneurysm and a ruptured aneurysm.

Key point: The media often does not distinguish between these two terms, so students can get confused as to their effects and treatment.

25. Describe all of the different physical, chemical, and neurological factors that can modify heart rate.

Key point: Explain to students that a wide variety of factors located all over the body can play a role in determining heart rate.

26. Discuss how concentration gradients (solute concentration) and pressure gradients (osmotic pressure) play key roles in nutrient and waste exchange at the capillary level.

Key point: This is a very important concept that challenges students. Tying in with the concepts learned in the cells and tissues chapter (Chapter 3) in the membrane transport section, students need to understand that solutes and water travel from an area of high concentration to low concentration, which allows for oxygen/carbon dioxide exchange, as well as nutrient/metabolic waste exchange at the cell/blood interface. This concept also provides a foundation for urine formation in the kidneys, discussed in the urinary system chapter (Chapter 15).

Classroom Demonstrations and Student Activities Classroom Demonstrations 1. Show a video of a beating heart, ideally with heart sounds. Emphasize the observation that while the right side of the heart is a pulmonary pump and the left side is a systemic pump, both atria contract at the same time and both ventricles contract at the same time.

2. Use a dissectible heart model to show heart structure.

3. Use a sheep’s heart (potentially with the ELMO, depending on classroom size) and point out superficial structures. Then section the heart coronally so that students can view the interior heart chambers and structures. Discuss blood flow through the heart.

4. Use a dissectible human torso model to point out the major arteries and veins of the body.

5. Show the chordae tendineae, the “heartstrings,” on a dissected heart, and demonstrate how they function to prevent backflow of blood into the atria during ventricular systole.

Note the difference between the papillary muscles and the trabeculae carnae.

6. Show a video of “hands only” CPR (newsroom.heart.org/multimedia/animationvideo/cpr-and-aeds-9749/cpr-and-aeds 7. Play a recording of normal and abnormal heart sounds to draw out or use images of how valves function and malfunction. (Interpreting Heart Sounds is available for loan from local chapters of the American Heart Association.)

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8. Demonstrate the recording of an ECG. Have one student come up to the front of the class. Explain placement of the electrodes and why it is important to have the patient completely still (have the student move around while attached to the ECG).

9. Show various ECGs of normal individuals and those with various pathologies. Briefly go over the differences.

10. Show a video of beating cardiac cells or tissue in a petri dish to show its autorhythmic nature.

11. Have a guest speaker from the American Heart Association talk to the class about the risk factors and leading causes of heart disease.

12. Bring in an old mechanical pacemaker and show its placement on the chest wall under the skin. Compare the heart’s own pacemaker, the SA node, to the implanted mechanical device, explaining that artificial pacemakers keep a set pulse rate and are not regulated by increased or decreased activity.

13. Demonstrate the use of defibrillators, including AEDs, and explain their function in cardiac rescue. Also discuss CPR as it relates to heart function.

14. Schedule CPR certification training opportunities for the students with the American Red Cross.

15. Show pictures of and describe “pitting” edema. Explain how fluid can fill the interstitial spaces to such a degree that an indentation will stay when the skin is pressed with the index finger.

16. Obtain synthetic bypass graft material and compare it in use and effectiveness to the preferred saphenous vein.

17. Describe the different symptoms of impending myocardial infarction (heart attack) in men and women. Provide statistics showing the increase in diagnosis of MI in women.

18. Discuss stents and angioplasties in treatment of heart disease. Bring in a stent to pass around if possible.

Student Activities 1. Have students take red (oxygenated blood) and blue (deoxygenated blood) yarn and pass the yarn through their respective routes using plastic or paper models from the heart to the lungs (blue yarn) and from the lungs to the heart (red yarn).

2. Demonstrate the location of the radial, brachial, carotid, femoral, popliteal, and pedal pulses. Have students locate several pulses of their own and compare their rate and rhythm. Discuss the clinical implications of weak or absent pulses in the extremities.

3. Demonstrate the auscultatory method of taking blood pressure and provide sphygmomanometers and stethoscopes for students to practice on each other.

4. Ask students to bring in a daily record of their blood pressure in the upright and supine positions for a specified period of time to chart and compare.

5. Provide simple drawings of a dissected heart and have the students follow the path of blood as it flows through the various chambers. Ask them to use red and blue pencils to differentiate between oxygenated and deoxygenated blood. Also ask them to label the chambers, valves, septa, and other distinguishing features. ..

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6. Have students trace the pathway of oxygenated, deoxygenated, and mixed blood in the fetal heart using a prepared diagram. Have students label the structures where blood is mixed.

7. Have students run in place or do jumping jacks for three minutes, then have them record their radial pulse (pointing out that a radial pulse is always thumb side). Have them continue to take their pulse every 30 seconds for five minutes, and then graph the results.

Point out that a steep decline in the first minute or so indicates rapid recovery by the heart.

8. Have students take their resting heart rate (beats/minute). Given the average stroke volume of 70 ml per beat, have them calculate cardiac output (heart rate  stroke volume).

Repeat after running or doing jumping jacks for three minutes (as in #7). Have students calculate cardiac output again to observe the effects of exercise on the amount of blood ejected by a ventricle per minute.

9. Provide the students with a diagram of the major blood vessels for labeling. For further help, allow students to work with a dissectible human torso model to allow them a more three-dimensional view of the vessels.

10. Have students list factors that increase or decrease cardiac output, and whether a specific factor affects stroke volume or heart rate or both.

11. Have students record their salt intake for one week. Provide them with a chart showing salt content in foods and also review the use of food labels. Have them graph their daily salt intake and compare it to the FDA limit. Discuss which foods, like milk products and pickles, are surprisingly high in salt content.

12. Have students “follow a drop of blood” as it travels through the body—for example, trace a drop of blood from the heart to your hands. This can be done with a blood vessel model board, diagram, or picture to help students understand route of blood flow.

13. Have students plan an investigation to learn more about heart rate and heart sounds. Have them select a problem, such as the relationship of age or weight, and determine its effect on heart rate and heart sounds. Have them formulate a testable hypothesis and list the steps for the investigation, including the selection of appropriate equipment and technology. They should implement the investigation, record the data in a chart, and draw conclusions from that data.

14. Have students plan an investigation to determine the effect of time of day on a selected vital sign. They should formulate a testable hypothesis and list the steps in the investigation to test this hypothesis, including the equipment and technology that would be used.

With your approval, students should then implement their plan using their classmates as subjects. They should record the data and draw conclusions about the effect of time of day on the selected vital sign.

15. Have a student perform an incremental stationary bicycle test and record heart rate and blood pressure from rest to exhaustion. Note how systolic blood pressure increases at higher exercise workloads and diastolic blood pressure remains nearly the same (important because diastole is when the heart is able to feed itself).

16. Create a classroom obstacle course following the route of blood that students must navigate.

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17. Have students dissect a cow’s heart both coronally and transversely to observe the differences in valves, chambers, wall thickness, and right/left sides.

Media See page 164 for a listing of media resources.

1. Watch, Learn and Live: Interactive Cardiovascular Library (AHA: 2016, watchlearnlive.heart.org). Interactive learning website for various cardiovascular functions and conditions.

2. Circulatory System (IM: 30 min., 2005, DVD). Examines the structure and functions of the circulatory system, using high-quality microscopic images.

3. Map of the Human Heart (PBS, 2011, www.pbs.org/wgbh/nova/body/map-humanheart.html). PBS Nova provides an interactive map of the human heart for students to explore various aspects of heart anatomy and blood flow.

4. Human Body: The Cardiovascular System (AMB: 29 min., 2010). Examines the anatomy and physiology of the cardiovascular system with the help of 3-D graphics, medical imaging, and cadaver specimens.

5. Cardiovascular System Introduction (Khan Academy: 2016, www.khanacademy.org/science/health-and-medicine/human-anatomy-andphysiology/heart-introduction/v/meet-the-heart). Videos, tutorials, flashcards, and quizzes about the cardiovascular system.

6. The Heart, Part 1: Under Pressure (Crash Course: 11 min., 2015, ca.pbslearningmedia.org/resource/heart-arteries-veins-video-crashcourse-1025/the-heartpart-1-under-pressure-crash-course-ap-25). Discusses heart anatomy, as well as a brief introduction to blood flow and pressure.

7. The Heart, Part 2: Heart Throbs (Crash Course: 10 min., 2015, ca.pbslearningmedia.org/resource/heart-circulation-pacemaker-video-crashcourse1026/the-heart-part-2-heart-throbs-crash-course-ap-26). Discusses the electrical conduction of the heart.

8. The Hidden Epidemic (PBS: 116 min., 2007, DVD). Personal vignettes and treatment strategies for heart disease.

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CHAPTER

12

The Lymphatic System and Body Defenses

Chapter Summary One of the least recognized of the body systems, the lymphatic system has been gaining ground in recognition and understanding over the past two decades, largely due to research into AIDS, cancer, and autoimmune disorders. The structural components of this system— lymphoid organs, tissue, lymph fluid, and white blood cells—are important players in the body’s immunity against invading and infiltrating pathogens. Although familiar with the idea of immunity, students are usually unfamiliar with the complementary role it plays with the cardiovascular system, as it surveys, filters, and cleanses leaked plasma before it is returned to the bloodstream.

The two semi-independent parts of the lymphatic system are presented first, beginning with the lymphatic vessels and followed by the lymphoid tissues and organs. Next is a full description of body defenses, beginning with an explanation of the nonspecific, innate defenses such as the epithelial barriers, as well as the cells and their secreted chemicals that attack anything appearing foreign to the body. The discussion then moves on to the specific, adaptive immune response that is tailored to combat specific pathogens efficiently and effectively.

The two types of cells that mediate the adaptive immune response are the B cells and T cells. Humoral (antibody-mediated) immunity is described first, highlighting the various roles of the B cells and explaining the differences between active and passive types of humoral immunity. Cellular (cell-mediated) immunity is presented next, along with a description of how T cells identify and combat specific foreign antigens that have infiltrated body cells.

The final section of this chapter discusses homeostatic imbalances of the immune system.

Organ transplantation and its associated risk of rejection are explained, along with allergies, immunodeficiencies, and autoimmune disorders. Finally, developmental aspects of the immune system are discussed: (1) during early development, T and B cells undergo “education” to distinguish between self and foreign antigens; (2) later on in life there is a dynamic interaction between the immune system and the environment; and (3) aging decreases the effectiveness of the immune system.

Suggested Lecture Outline Part I: The Lymphatic System (pp. 392–397) I. 12.1 Lymphatic Vessels (pp. 393–394) II. 12.2 Lymph Nodes (pp. 394–396) III. 12.3 Other Lymphoid Organs (pp. 396–397) 127 INSTRUCTOR GUIDE FOR ESSENTIALS OF HUMAN ANATOMY & PHYSIOLOGY, 13e

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Part II: Body Defenses (pp. 397–423) I. 12.4 Innate Body Defenses (pp. 398–405) A. 12.4a Surface Membrane Barriers: First Line of Defense (pp. 398–400) B. 12.4b Cells and Chemicals: Second Line of Defense (pp.

400–405) 1. Natural Killer Cells 2. Inflammatory Response 3. Phagocytes 4. Antimicrobial Proteins a. Complement b. Interferon 5. Fever

II. 12.5 Adaptive Body Defenses (pp. 405–423) A. 12.5a Antigens (p. 406) B. 12.5b Cells of the Adaptive Defense System: An Overview (pp. 406–408) 1. Lymphocytes 2. Antigen-Presenting Cells C. 12.5c Humoral (Antibody-Mediated) Immune Response (pp. 409–414) 1. Active and Passive Humoral Immunity 2. Antibodies a. Basic Antibody Structure b. Antibody Classes c. Antibody Function D. 12.5d Cellular (Cell-Mediated) Immune Response (pp.

414–416) E. 12.5e Organ Transplants and Rejection (pp. 416, 420– 421) F. 12.5f Disorders of Immunity (pp. 421–424) 1. Allergies 2. Autoimmune Diseases 3. Immunodeficiencies

TEACHING TIP As with all body systems, nothing works in isolation in the immune system, as immune system cells perform supportive and coordinated roles. It is important to emphasize to the students the cross-communication that occurs between cells that are categorized into different branches of immunity. For example, the macrophages that have their own roles in innate defense also play an important role in antigen presentation to the cytotoxic T cells in the cell-mediated response. The helper T cells, members of cellmediated immunity, are not only essential for cytotoxic T cell function, but also are key in triggering B cell response in the humoral arm of the adaptive immune response.

MEDIA TIP Fever! (PBS Learning Media, 8 min., 2016, http://www.pbslearningmedi a.org/resource/tdc02.sci.life. reg.fevervid/fever/). Discusses how fever can be a beneficial homeostatic mechanism by the body.

Part III: Developmental Aspects of the Lymphatic System and Body Defenses (pp. 424–425) Note: For a list of Key Terms for this chapter, please go to Mastering A&P > Study Area > Additional Study Tools > Key Terms > Chapter 12.

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Learning Objectives 12-1 Explain how the lymphatic system is functionally related to the cardiovascular and the immune defenses.

12-2 Name the two major types of structures composing the lymphatic system.

12-3 Describe the source of lymph, and explain its formation and transport.

12-4 Describe the function(s) of lymph nodes, tonsils, the thymus, Peyer’s patches, and the spleen.

12-5 Describe the protective functions of skin and mucous membranes.

12-6 Explain the role of natural killer cells.

12-7 Describe the inflammatory process.

12-8 Explain the importance of phagocytes.

12-9 Name several antimicrobial substances produced by the body that act in innate body defense.

12-10 Describe how fever helps protect the body.

12-11 Define antigen and hapten, and name substances that act as complete antigens.

12-12 Name the two arms of the adaptive defense system, and relate each to a specific lymphocyte type (B or T cell).

12-13 Compare and contrast the development of B and T cells.

12-14 State the roles of B cells and T cells.

12-15 Explain the importance of antigen-presenting cells in immunity.

12-16 Define humoral immunity.

12-17 State the role of plasma cells.

12-18 Explain the function(s) of antibodies, and describe clinical uses of monoclonal antibodies.

12-19 Distinguish between active and passive immunity.

12-20 Describe the structure of an antibody monomer.

12-21 List the five antibody classes, and describe their specific roles in immunity.

12-22 Describe several ways in which antibodies act against antigens.

12-23 Distinguish the roles of helper, regulatory, and cytotoxic T cells.

12-24 Describe allergies, autoimmune diseases, and immunodeficiencies.

12-25 Describe the origin of the lymphatic vessels.

12-26 Describe the effects of aging on immunity.

Resources for Teaching Online Discussion Board Topic: Homeostatic Imbalance—Systemic Lupus Erythematosus (SLE) In the textbook on page 423, the Homeostatic Imbalance section explains that systemic lupus erythematosus (SLE) is an autoimmune disease that affects the kidneys, heart, lungs, and skin in mostly young women. Engage your students by using the following discussion questions in lecture or by posting them to the discussion board on your course management system.

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Discussion Questions 1. What are common symptoms of patients suffering from lupus?

2. Diagnosing lupus sometimes takes years. Why is it so hard to diagnose?

3. Why do researchers think that estrogen, along with genetics and environment, is involved in lupus development?

4. What are some treatment options for lupus?

Potential Student Responses 1. Some symptoms that may be observed in lupus patients are a red “butterfly/malar” rash on the face around the cheeks and nose, extreme fatigue, fever without other infection, neurologic disorders such as seizures or psychosis, chest pain when breathing deeply, unusual loss of hair, sun sensitivity, edema in legs and/or around eyes, excessive protein in the urine, mouth ulcers, swollen glands, arthritis, anemia, and pale/purple fingers or toes from cold or stress.

2. This is a complex disease that manifests differently in different individuals. Although there are some common symptoms, different symptoms can arise at different periods, even in the same individual. The disease can affect one organ system or multiple systems. Therefore, the symptoms can be similar to those of a number of different diseases.

Unless the physician is aware of the patient’s complete medical history of all the symptoms that come and go, lupus may not be diagnosed. Standard testing of lupus is done with an initial antinuclear antibody (ANA) test. If a patient tests positive on an ANA test, a subsequent ANA panel test may be done, including anti–double-stranded DNA and anti-Smith, anti-U1RNP, anti-Ro/SSA, and anti-La/SSB screening. This panel can help physicians try to rule out other infections or autoimmune disease that can also lead to a positive ANA result.

3. This disease primarily affects young women (childbearing age); 90 percent of lupus patients are in this population. Women who are postmenopausal are much less likely to develop lupus, or for those that do have lupus, the flare-ups are much less frequent as compared to younger women with the disease. Additionally, postmenopausal lupus patients who have undergone estrogen replacement therapy have higher incidences of flareups.

4. Lupus can only be treated at this time and not cured. Treatments include antiinflammatory drugs, such as corticosteroids with or without antimalarial co-treatment, immunosuppressives monoclonal antibodies, and aspirin. In addition, lupus patients have accompanying health issues that will also need to be treated. For example, diuretics are administered to lower fluid retention, as well as anti-hypertensives to counteract accompanying high blood pressure, anticoagulants to prevent blood clots, and anticonvulsants if seizures accompany the disease.

Investigate Online Take learning a step further by searching for relevant research articles on the web. Visit science websites, such as those listed below, and begin by searching for key terms such as lupus, systemic lupus erythematosus (SLE), and antinuclear antibodies and see how what you’re learning in the course applies to science and medicine today.

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www.sciencedaily.com www.scientificamerican.com www.the-scientist.com www.ncbi.nlm.nih.gov/pubmed www.lupus.org/research-news

Study Tips Direct students to the Study Tips feature located in the front of the book.

Mastering A&P Numerous items from Mastering A&P can be demonstrated in class, assigned as homework, or encouraged as study materials. These include practice tests and quizzes, animations and videos, Interactive Physiology (IP), Dynamic Study Modules, Audio Journeys, Practice Anatomy Lab (PAL), PhysioEx, flashcards, glossary, key terms, and more.

Interactive Physiology (IP) The following sections of Interactive Physiology are relevant to this chapter: Lymphatic System IP Animation: Lymphatic Organs Immune System IP Anatomy Review Animation: Immune IP Animation: Innate Internal Defenses IP Animation: Class I and Class II MHC Proteins IP Animation: Overview of Innate and Adaptive Body Defenses

Practice Anatomy Lab (PAL)3.1: Including Mobile Flashcards The following sections of PAL3.1 are relevant to this chapter:

Human Cadaver > Lymphatic System

Anatomical Models > Lymphatic System

Histology > Lymphatic System

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Lecture Hints 1. Compare and contrast lymph vessels and blood vessels.

Key point: Blood vessels form a closed loop or circuit, whereas lymphatic vessels are an open, one-way system. Arteries have a pump (the heart) behind them helping to push fluids along, whereas lymphatic vessels are pumpless (and thus a pulse cannot be felt).

Veins and lymphatic vessels are similar in that they are both thin walled and have oneway valves, and both rely on the milking action of the muscle pump system and pressure changes in the thorax to move fluids along against gravity.

2. Outline the location and origin of lymph fluid, starting with blood plasma. Describe how it is called interstitial fluid once it is pushed out of the blood vessels, that it becomes lymph fluid when picked up by the lymphatic vessels, and, finally, that it is again called blood plasma upon its return to the cardiovascular system after cleansing.

Key point: Point out that this is all the same fluid but that it is called different things depending upon its location at any given time. However, the composition of the solutes may differ slightly at the different locations.

3. Reinforce that the right lymphatic duct drains one-fourth of the body (the upper right quadrant) and the thoracic duct drains the remaining three-fourths of the body.

Key point: The asymmetry of this system is often confusing for students at first.

4. Discuss the importance of the gut microbiota.

Key point: Students may be surprised to learn that all bacteria are not harmful; gut microbiota establishment is necessary for pre- and postnatal development, regulation of metabolism, and adaptive immunity development, as well as preventing colonization of pathogenic bacteria within the gut.

5. Explain the various schools of thought related to tonsillectomy and adenoidectomy (T&A).

Key point: Removal of the tonsils and adenoids following repeated upper respiratory infections is still practiced, although not to the degree it was in generations past. Increased awareness of the role of the lymphatic system in fighting disease has made it less desirable to remove lymphoid tissue during transient illnesses than in previous years. However, in situations where there are five to seven episodes of tonsillitis per year for multiple years, with accompanying issues of breathing difficulty, tonsillectomies may be performed in adults. In children, tonsillectomies are not recommended unless there are more than seven episodes in one year, five episodes each year for two years, or three episodes each year for three years.

6. Discuss how mucosa-associated lymphatic tissue (MALT) is found in areas where there are orifices open to the interior of the body (digestive and respiratory systems) and how the appendix serves an important immunological role.

Key point: The tissue is strategically located to deal with invading pathogens in areas open to the outside environment. Often, students have the misconception that the appendix is a vestigial structure with no function. Emphasize that it plays an important role as a sentry to control bacterial growth in the beginning portion of the large intestine, as well as deterring bacteria from invading the small intestine.

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7. List the numerous functions of the spleen, as well as the causes and consequences of splenomegaly. Explain the theories behind splenectomy for thrombocytopenia and nonHodgkin’s lymphoma.

Key point: The spleen’s numerous cleansing functions include control of encapsulated bacteria in the blood and destruction of old RBCs. Cirrhosis and heart failure can lead to spleen enlargement. In thrombocytopenia, the spleen eliminates platelets at a rate faster than they can be replaced, and one treatment option is removal of the spleen to prevent further platelet destruction. For non-Hodgkin’s lymphoma, splenectomy may be done as palliative care for such conditions as thrombocytopenia.

8. List redness, heat, swelling, and pain as the four cardinal signs of the inflammatory response, and emphasize that fever and heat are not the same thing. Note that fever is NOT a symptom of this response. Also note that although inflammation is sometimes painful, students need to understand that the response is a beneficial, essential defense mechanism that paves the way for proper tissue repair. Finally, note that animals with higher body temperatures are generally more resistant to disease.

Key point: Fever is a separate nonspecific defense mechanism. A fifth sign is occasionally listed as part of the inflammatory response, and that sign is decreased joint movement resulting from swelling. Redness and heat signify blood flow into the injured area, while pain and swelling caused by edema are protective against movement of the injured area that could lead to either spreading of an invading pathogen to the rest of the body, or further damage to the area.

9. Note that complement proteins represent a nonspecific defense, even though they may be activated as part of a specific response to an antigen. Also point out that complement fixation represents another example of positive feedback.

Key point: The mechanism of complement fixation is often poorly understood by students and warrants extra time for discussion.

10. Discuss the similarities and differences between natural killer cells and killer T cells.

Key point: Although natural killer (NK) cells are part of the innate defense arm and killer T cells are part of the adaptive defense arm, they have some similarities. They both kill virally infected cells and cancer cells, but the T cells are specific to a specific virally infected cell or tumor cell, whereas NK cells are nonspecific. Both types of cells use perforin and granzymes to punch holes in the target cell’s membrane to cause apoptosis (programmed cell death). Also, a very important point to emphasize is that killer T cells need to have another cell such as a macrophage, dendritic cell, or B cell to present the foreign antigen to mount a response, whereas NK cells do not.

11. Relate the antibodies that cause transfusion reactions (Chapter 10) to the antibodies against pathogens such as bacteria.

Key point: This comparison will show students that the antibodies in both situations act the same to stop a foreign invader, whether it is a foreign blood cell or a disease-causing agent. Students should be able to tie in concepts from Chapter 10.

12. Discuss antihistamines and explain when and why they are taken, as well as the role of IgE in necessitating their use. Also discuss why antihistamines are ineffective against delayed hypersensitivities.

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Key point: Antihistamines are used to treat allergies, hives, and other hypersensitivity reactions brought about by IgE. Delayed hypersensitivities are mediated by T cells and macrophages that release cytokines rather than histamines, so blocking histamine action in this situation is ineffective.

13. Explain the symptoms of anaphylactic shock and the necessary treatment for this lifethreatening condition.

Key point: Anaphylactic shock is a reaction between allergic antigens and IgE. It can only occur following previous exposure to the specific allergic antigen, and it results in bronchospasm, laryngeal edema, and circulatory collapse. Untreated, it can be fatal.

Common treatments are epinephrine with oxygen, intravenous antihistamines with corticosteroids, and albuterol.

14. Discuss autoantibodies as the basis for autoimmune diseases such as rheumatoid arthritis, myasthenia gravis, multiple sclerosis, and Graves’ disease. Use the example of antisperm antibodies produced following vasectomy, and note that after 7 to 10 years there is such an abundance of the antibodies circulating in the bloodstream that attempts at vasectomy reversal after that length of time are usually unsuccessful.

Key point: Autoantibodies are produced by B cells in response to altered autoantigens, or “self-antigens,” although the reasons for this reaction are still being researched.

15. Describe organ transplantation, including the types of organs that can be transplanted and what happens if the body rejects the transplant. Explain why corneal and lens transplants are so successful.

Key point: Students are usually unaware of the large number of organs that can be transplanted and may be more willing to become organ donors as a result. Corneal transplants are less likely to experience rejection, as there is no direct blood supply, and thus less exposure to antibodies. Also, an artificial lens is transplanted; therefore, no antigens are on the synthetic lens, and thus antibodies will not be generated.

16. Emphasize the importance of breast-feeding infants when possible.

Key point: Stress the importance of antibody transfer from mother to infant to provide some immunological protection from infection, as the infant immune system is not yet well developed. The passive immunity can be quite effective, because often the mother will encounter the same pathogens to which the infant also is exposed.

17. Explain the use of an immunoglobulin injection before traveling to remote areas.

Key point: Discuss with students the benefits of an immune “boost” when they may be exposed to new antigens and medical help may not be immediately available.

18. Discuss how antivenom is created and why it, rather than a vaccine, is given after a poisonous snakebite.

Key point: Students are fascinated by the fact that antivenom is made by inoculating other animals such as sheep, rabbits, dogs, and horses with the actual snake venom to generate antibodies that are later processed and purified for human use. Have students reason out that the time period for mounting a secondary immune response would take too long; the antibodies must be administered quickly to combat the venom that is already in the body.

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Classroom Demonstrations and Student Activities Classroom Demonstrations 1. Show videos of a macrophage phagocytizing a bacterium and a CTL killing a target cell and discuss the difference in mechanisms.

2. Use the torso model or lymphatic system board to demonstrate the location of the lymphoid organs and tissues.

3. Invite a speaker from the local public health department to present the most current information on AIDS. 4. Go to the HHMI Biointeractive website and do the Immunology Virtual Lab activity with the class. www.hhmi.org/biointeractive/immunology-virtual-lab 5. Invite speakers to talk to the class about treatment options, current research, and issues related to living with multiple sclerosis, rheumatoid arthritis, myasthenia gravis, Graves’ disease, type I diabetes mellitus, lupus, or any other immune-related disorder.

6. Invite a speaker from the local public health department to outline vaccine schedules as required or recommended by the government. Discuss current issues surrounding public resistance to vaccines, their benefits as well as potential side effects, and the debate about choice, especially with the recent discussion regarding autism.

7. Use video presentations and images to contrast the four major kinds of grafts: autografts, isografts, allografts, and xenografts. List the advantages and disadvantages of each.

8. Generate a chart for use in class to compare and contrast how B and T cells work.

9. Discuss why some diseases are fatal when contracted, such as Ebola and other hemorrhagic fevers.

10. Go through the activity of making a vaccine through the interactive activity found at www.pbs.org/wgbh/nova/body/making-vaccines.html.

Student Activities 1. Use WARD’s Simulated Disease Transmission Lab Activity. This is a fun, eye-opening activity that helps students understand the field of epidemiology and the speed and extensiveness with which diseases spread.

2. Ask students to research communicable diseases and present their findings on the top 10 diseases in their local area compared to the national figures. Assist them in accessing information from the Centers for Disease Control and Prevention.

3. Student assignment for class discussion: Have students research the factors on determining prescription drug pricing, from research and development (R&D) to placement in a pharmacy. Students may also debate the ethics of pricing of HIV medicines or, more recently, the EpiPen. 4. Distribute cutouts/figures of bacteria, viruses, and all types of leukocytes—one cutout per student. Have students simulate, in order, the first, second, and third lines of defense.

5. Have students draw a concept map or outline of the processes of defense secondary to injury. Pose the question “What happens if the skin is penetrated and the pathogen enters the body?”.

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6. Ask students to research physical and psychological stress and its impact on the immune system. Contrast the difference between eustress (good stress) and distress (bad stress).

These are some examples: How does exercise affect the immune system? Does academic stress (such as finals) impact the immune system?

7. Student assignment for class discussion: Look up articles in the newspaper or popular magazines that concern the social, medical, and economic problems surrounding HIV/AIDS. Emphasize the global implications of this disease. A starting point for students can be found here: www.hiv.gov/federal-response.

8. Have students research flu pandemics: why they occur, how they spread, and so on. Also, why were the avian flu and swine flu considered to be so dangerous?

9. Have students research how the annual flu vaccine is made. Why is the designated flu vaccine ineffective in certain years? Also, have students research the different types of flu vaccine available and if there is a difference in how they are created.

10. Have students investigate how genomic profiling of tumors and patients are used in personalized cancer therapy.

11. Have students investigate how researchers are using the strategy of immunotherapy (Tcell stimulation) in cancer.

12. Have students debate whether or not children should be administered the human papillomavirus (HPV) vaccine.

13. Have students play the immune responses game, either as a class or in small groups: immunequest.com. There are a number of games based on the immune system at educationalgames.nobelprize.org/educational/medicine/immuneresponses/.

14. Create a Jeopardy-style PowerPoint (students can submit questions and answers beforehand or work in groups to create versions) and use topic headings such as those used in the chapter: internal defenses, cells and chemicals, adaptive body defenses, and so on.

15. Have students research prions and the diseases they cause.

16. Have students report on the current status of edible vaccine development.17. Have students select one of the COVID-19 vaccines authorized for use in the United States (Moderna, Pfizer, etc.) to research in terms of how it works in the body and the challenges related to its large-scale distribution. www.nytimes.com/interactive/2020/health/moderna-covid-19-vaccine.html

Media See page 164 for a listing of media resources.

1. HIV/AIDS 101 (CDC: 7 min., 2012, www.cdc.gov/cdctv/diseaseandconditions/hiv/hivaids-101.html). Informational video by the CDC about HIV/AIDS symptoms, transmission methods, testing, and prevention.

2. How Do Allergies Work? (WebMD: 2 min., 2015, www.webmd.com/allergies/video/allergic-reactions). Brief video on the mechanisms of allergies.

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3. An Inside Look: The Flu (JE: 27 min., 2000, DVD). This exceptional video illustrates how cells of the immune system fight to protect the body against invasion by the influenza virus.

4. Living with Arthritis (FHS: 28 min., 2005, VHS, DVD, 3-year streaming webcast). This program covers treatment protocols, warning signs, and the impact of living without treatment, and includes medical commentary from the expert who created joint implants.

5. Out of Control: AIDS in Black America (FHS: 41 min., 2006, VHS, DVD, 3-year streaming webcast). Investigative journalist Peter Jennings covers the rise in AIDS among the African American community and includes candid discussions with several black leaders.

6. Lymphatic System Introduction (Khan Academy, 2013, www.khanacademy.org/science/health-and-medicine/human-anatomy-andphysiology/lymphatics/v/why-do-we-need-a-lymphatic-system). Introduction to the lymphatic system.

7. Fight Germs, Wash Your Hands! (CDC: 3 min., 2016, www.cdc.gov/cdctv/healthyliving/hygiene/fight-germs-wash-hands.html). Proper handwashing technique is demonstrated.

8. Human Immune System (IM: 20 min., 2002, DVD). Explains how the immune system defends the body against foreign invaders.

9. Vaccines: Calling the Shots (PBS: 54 min., 2014, DVD). Explains the need for vaccinations and the dangers of being unvaccinated.

10. Influenza (FHS: 28 min., 2005, VHS, DVD, 3-year streaming webcast). Examines the factors of transmission of the flu, including dangers to high-risk groups.

11. Venom: Nature’s Killer (PBS, 53 min., 2012, DVD, webcast). This video discusses the harnessing of venom poison as potential treatment for cancer and other serious illnesses.

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CHAPTER

13

The Respiratory System

Chapter Summary The respiratory system is intimately connected to the cardiovascular system, both in location and function. Together, they work to supply all body cells with oxygen and dispose of metabolic end products such as carbon dioxide. The systems work interdependently with one another and are considered to be one of the most important homeostatic organ system teams in the body.

The first section of this chapter outlines the functional anatomy of the respiratory system.

The order of air entry is as follows: nose, pharynx, larynx, trachea, bronchi, and terminal bronchioles. These structures are known as conducting zone structures. Conducting zone structures allow air to reach the lungs, as well as purify, humidify, and warm the incoming air along the way. The lungs are presented next, including a review of their basic structure and position. The respiratory zone structures, comprising the respiratory bronchioles, alveolar ducts, alveolar sacs, and alveoli within the lungs, are the actual sites of external respiratory gas exchange. The respiratory membrane is the interface between the respiratory and circulatory systems, where gas exchange through simple diffusion occurs. This membrane, therefore, is also known as the blood air barrier.

The next section of this chapter presents respiratory physiology and the mechanics of the four distinct events of respiration: pulmonary ventilation, external respiration, respiratory gas transport, and internal respiration. The contraction and relaxation of surrounding muscles leading to volume changes in the thoracic cavity, and their relation to pressure changes in the area that allow for inspiration and expiration to occur, are then explained. The respiratory volumes are outlined, including tidal volume, inspiratory reserve volume, expiratory reserve volume, residual volume, and vital capacity. Next, the chapter discusses the mechanisms of external respiration and the actual exchange of gases between the alveoli and the blood. Then follows a description of the gas transport process in blood, followed by an explanation of internal respiration, where gas exchange occurs between the systemic capillaries and the tissues. The factors involved in control of respiration are also described, including neural regulation, volition, emotional factors, and chemical factors.

The final section of this chapter addresses commonly observed respiratory disorders and age-related changes in the respiratory system.

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Suggested Lecture Outline I. 13.1 Functional Anatomy of the Respiratory System (pp. 432–441) A. 13.1a The Nose (pp. 433–434) B. 13.1b The Pharynx (pp. 434–435) C. 13.1c The Larynx (pp. 435–436) D. 13.1d The Trachea (p. 436) E. 13.1e The Main Bronchi (pp. 436–437) F. 13.1f The Lungs (pp. 437–441) 1. The Bronchial Tree 2. Respiratory Zone Structures and the Respiratory Membrane

TEACHING TIP Students initially have difficulty with respiratory volumes and capacities.

Demonstrate in front of class each component of vital capacity and also residual volume. Help students conceptualize the components of breathing by demonstrating the actual actions of inspiration and expiration, and have the students follow suit, while pointing to each component graphed in Figure 13.9.

Students will then realize that the respiratory volumes and capacities are straightforward, easy-to-understand concepts.

II. 13.2 Respiratory Physiology (pp. 441–450) A. 13.2a Mechanics of Breathing (pp. 441–444) 1. Inspiration 2. Expiration B. 13.2b Respiratory Volumes and Capacities (pp. 444– 445) 1. Nonrespiratory Air Movements 2. Respiratory Sounds C. 13.2c External Respiration, Gas Transport, and Internal Respiration (pp. 445–448) 1. External Respiration 2. Gas Transport in the Blood 3. Internal Respiration D. 13.2d Control of Respiration (pp. 448–450) 1. Neural Regulation: Setting the Basic Rhythm 2. Nonneural Factors Influencing Respiratory Rate and Depth a. Physical Factors b. Volition (Conscious Control) c. Emotional Factors d. Chemical Factors

MEDIA TIP Understanding the Risks of Tobacco and Caffeine (FHS: 29 min., 1998). From the series Substance Abuse: Risks and Responsibilities, this video addresses the major health risks associated with smoking tobacco and the excessive drinking of caffeinated beverages, with emphasis on lung cancer and other smoking-related conditions.

III. 13.3 Respiratory Disorders (pp. 450–453) A. Chronic Obstructive Pulmonary Disease (COPD) (p. 451) B. Lung Cancer (pp. 451–453)

IV. 13.4 Developmental Aspects of the Respiratory System (pp. 453, 455) Note: For a list of Key Terms for this chapter, please go to Mastering A&P > Study Area > Additional Study Tools > Key Terms > Chapter 13.

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Learning Objectives 13-1 Name the organs forming the respiratory passageway from the nasal cavity to the alveoli of the lungs (or identify them on a diagram or model), and describe the function of each.

13-2 Describe several protective mechanisms of the respiratory system.

13-3 Describe the structure and function of the lungs and the pleural coverings.

13-4 Describe the structure of the respiratory membrane.

13-5 Define cellular respiration, external respiration, internal respiration, pulmonary ventilation, expiration, and inspiration.

13-6 Explain how the respiratory muscles cause volume changes that lead to air flow into and out of the lungs (breathing).

13-7 Define the following respiratory volumes: tidal volume, vital capacity, expiratory reserve volume, inspiratory reserve volume, and residual air.

13-8 Name several nonrespiratory air movements, and explain how they modify or differ from normal respiratory air movements.

13-9 Describe the process of gas exchanges in the lungs and tissues.

13-10 Describe how oxygen and carbon dioxide are transported in the blood.

13-11 Name the brain areas involved in control of respiration.

13-12 Name several physical factors that influence respiratory rate.

13-13 Explain the relative importance of oxygen and carbon dioxide in modifying breathing rate and depth.

13-14 Explain why it is not possible to stop breathing voluntarily.

13-15 Define apnea, hyperventilation, and hypoventilation.

13-16 Describe symptoms and probable causes of COPD and lung cancer.

13-17 Describe normal changes that occur in respiratory system functioning from infancy to old age.

Resources for Teaching Online Discussion Board Topic: Homeostatic Imbalance—Cystic Fibrosis In the textbook on page 453, the Homeostatic Imbalance section discusses cystic fibrosis, the most common lethal genetic disease in the United States. This disease causes thick mucus that impairs not only the respiratory system but also processes in the digestive and integumentary system due to impaired Cl− secretion. Engage your students by using the following discussion questions in lecture or by posting them to the discussion board on your course management system.

Discussion Questions 1. What are the common symptoms associated with cystic fibrosis?

2. How is cystic fibrosis diagnosed?

3. Who is at risk for this disease?

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Potential Student Responses: 1. Salty-tasting skin, nasal polyps, greasy stool, poor birth weight or weight gain with a healthy appetite, frequent coughing, frequent lung infections, and wheezing and shortness of breath.

2. Neonatal or early childhood screenings are usually done (immunoreactive trypsinogen [IRT] test); if symptoms are observed, the most common way cystic fibrosis is diagnosed is through the sweat test. An electrode placed on the skin stimulates sweat secretion and the level of chloride in the sweat is measured; 60 mmol/l chloride or above indicates cystic fibrosis. Genetic tests can also be conducted.

3. Cystic fibrosis strikes about an average of 1 in 3,200 to 3,500 Caucasian newborns, 1 in 9,200 to 9,500 Latinos, 1 in 15,000 to 17,000 African Americans, and 1 in 31,000 Asian Americans. It appears to be caused by mutations in a gene named CFTR. Normally this gene directs the production of a protein channel that transports chloride ions across the cell membrane. The mutation affects this exchange. This mutation is an autosomal recessive mutation, meaning the child has to receive a faulty gene from each parent to be affected.

4. Some examples include investigating modifier genes (genes that affect the severity of the disease) so that more custom-tailored treatment strategies can be offered in the future, assessing the needs of patients who are living past adolescence, gene therapy delivery strategies, CFTR modulator drugs, developing better antibiotics for infections in patients, and altering mucus and airway surface liquid, among others. It is estimated that 80 percent of current patients will live to adulthood and into their 40s in the United States.

Investigate Online Take learning a step further by searching for relevant research articles on the Web. Visit science websites, such as those listed below, and begin by searching for key terms such as cystic fibrosis, cystic fibrosis therapy, cystic fibrosis gene therapy, cystic fibrosis lung, cystic fibrosis pseudomonas, and cystic fibrosis pancreas and see how what you’re learning in the course applies to science and medicine today. www.sciencedaily.com www.scientificamerican.com www.the-scientist.com www.ncbi.nlm.nih.gov/pubmed

Study Tips Direct students to the Study Tips feature located in the front of the book.

Mastering A&P Numerous items from Mastering A&P can be demonstrated in class, assigned as homework, or encouraged as study materials. These include practice tests and quizzes, animations and videos, Interactive Physiology (IP), Dynamic Study Modules, Audio Journeys, Practice Anatomy Lab (PAL), PhysioEx, flashcards, glossary, key terms, and more.

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Interactive Physiology (IP) The following sections of Interactive Physiology are relevant to this chapter: Respiratory System IP Anatomy Review Animation: Respiratory IP Animation: Pulmonary Ventilation IP Animation: Control of Respiration IP Animation: Gas Exchange

PhysioEx10.0 The following sections of PhysioEx10.0 are relevant to this chapter:

Videos of PhysioEx Lab Experiments: Water-Filled Spirometer

Exercise 7: Respiratory System Mechanics

Animations and Videos The following animations and videos are relevant to this chapter:

Bio Flix > Gas Exchange

Bone and Dissection Videos > Fetal Pig Dissection > Structures of the Respiratory System

Practice Anatomy Lab (PAL)3.1: Including Mobile Flashcards The following sections of PAL3.1 are relevant to this chapter:

Human Cadaver > Respiratory System

Anatomical Models > Respiratory System

Histology > Respiratory System ..

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Cat > Respiratory System

Fetal Pig > Respiratory System

Additional Study Tools The following video is relevant to this chapter:

Focus on Careers > Respiratory Therapist

Lecture Hints 1. Emphasize the interplay between the respiratory and cardiovascular systems.

Key point: Of all the systems, these two are the most intimately connected. We separate them for study purposes, but they must be considered as a functional team.

2. Clearly pronounce pharynx (far' inks) and larynx (lar' inks) and have students repeat the correct pronunciation of these two terms. Reinforce that the pharynx (throat) is shared by air and food (except the nasopharynx; only respiratory system) while the larynx (voice box) only has air passage.

Key point: These are two of the most commonly mispronounced words in science. Students usually say “far' niks” and “lar' niks” and are surprised to learn that they have been mispronouncing these words all their lives. This is a good time to help them break a bad pronunciation habit.

3. Discuss the structure and location of the vocal cords within the larynx.

Key point: When first learning the anatomy of the respiratory system, students often get confused as to the location and function of the thyroid cartilage (Adam’s apple), epiglottis, glottis, and true vocal cords. Distinguish the role of the epiglottis in swallowing (ensuring that food goes down the esophagus) versus the glottis and the vocal folds in sound production. It may be helpful to discuss the specific tissue composition of these structures to help students distinguish between them.

4. Discuss vocal cord nodules, polyps, and cysts.

Key point: Students often hear about how singers need to “rest their vocal cords” due to the formation of these lesions. Nodules are similar to callouses developing bilaterally at the midline of the vocal folds due to overuse; a polyp occurs on either one or both vocal folds and resembles a blister; and a cyst is a tissue mass encased in a membranous sac on the vocal fold. Students will be able to relate to disruption of structure causing a disruption of function. Overuse, trauma, or excess tension to the vocal folds are common causes of these lesions. Rest, voice therapy, treatment of underlying medical problems, or surgery may be done to alleviate the lesion.

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5. Discuss the purpose of the C rings (hyaline cartilage rings) of the trachea. Distinguish them from the underlying esophagus of the digestive system.

Key point: The C rings keep the trachea open for air flow, despite the pressure changes that occur during respiration. The esophagus does not need to remain open, as food travels after ingestion only in one direction—downward, toward the stomach. Point out that the C rings are made of hyaline cartilage.

6. Explain the function of the cough reflex to expel and prevent food from entering the lungs. Include a discussion of the Heimlich maneuver, which is used to dislodge an obstruction from the respiratory passages. Also correlate aspiration pneumonia to food or some other foreign object that has been inhaled into the respiratory passages and has not been successfully removed.

Key point: This helps students understand the seriousness of aspiration and helps them develop a sense of the many natural and artificial mechanisms employed to prevent this occurrence. Also discuss that food tends to become lodged in the right bronchus due to its wider, shorter, and straighter structure as compared to the left bronchus.

7. Discuss the differences between tracheostomy and tracheotomy.

Key point: Tracheostomy is the surgical opening into the trachea to provide a patent airway. Tracheotomy is the actual incision into the trachea to make the opening. Note that these two terms are often used as synonyms, even though medically they have distinct meanings.

8. Spend time differentiating between the visceral and parietal pleura. Note that the pain associated with pleurisy mimics that of the initial symptoms of a heart attack and results from these two membranes rubbing against each other like two pieces of sandpaper, rather than with the usual gliding motion.

Key point: The double layer of the pleura often confuses students, but they can usually visualize the friction that would result from two dry, rough surfaces rubbing together.

9. Emphasize the purely mechanical nature of inspiration and expiration. Explain that as the chest space expands, air will rush in to equalize the inner and outer pressures, and as the chest contracts, air will be pushed out again for the same reason. Point out that although the intercostal muscles are important at high levels of ventilation, it is the diaphragm that accomplishes most of the change in volume of the thorax during inspiration. Note that singers learn to control their diaphragm as they initiate sound from deep in their thorax.

Key point: It is important to emphasize the inverse relationship between pressure and volume. Inspiration and expiration processes will emphasize pressure gradients as well; point out the similarities to diffusion and osmosis.

10. Differentiate between atelectasis and pneumothorax. Explain that pneumothorax is just one of the many possible causes of atelectasis. Also, note that atelectasis literally means “incomplete expansion” and pneumothorax means “air in the chest.” Ask the students to then explain what hemothorax means. Describe the outcome of a sucking chest wound, such as might result from stabbing with a knife or piercing with a bullet or arrow.

Key point: With a sucking chest wound, a puncture opening allows air to suck into the chest, collapsing the lung as it fills the chest cavity. In an emergency situation, collapse of the lung is stopped or prevented by applying an occlusive bandage over the opening (about the size of a credit card). Draw a connection between atelectasis and pneumotho..

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rax with the concept of intrapleural pressure, noting that intrapleural pressure must be lower than intrapulmonary pressure for inspiration to occur.

11. Discuss the postoperative use of the incentive spirometer, which is the apparatus with the Ping-Pong ball in it. A postoperative patient is asked to inhale and suck the Ping-Pong ball to the top of the device, usually at least 10 times per hour.

Key point: This helps prevent pneumonia by keeping the lungs inflated while the patient is on bed rest. Historically, pneumonia was the leading cause of death in postsurgical patients, and this simple technique greatly reduces that risk.

12. Explain respiratory center failure and treatment options in such situations as cervical collapse of the spinal cord. Discuss ventilator dependency and the advent of phrenic pacing as an alternative in some cases. Students are usually familiar with the actor Christopher Reeves, and a discussion of his injury helps them understand the respiratory ramifications.

Key point: Spinal cord prolapse at the C1 and C2 levels results in respiratory failure, necessitating mechanical ventilation through a tracheostomy. C3 or higher quadriplegics are relatively rare as traumatic injury this high in the spinal column necessarily requires artificial ventilation within about 5 minutes after the injury in order to stay alive. The rhyme C3, 4, 5 helps you breathe to stay alive is easy to remember. In some cases, a phrenic pacing device similar to a cardiac pacemaker can be implanted into the chest wall to send electrical signals to the diaphragm, causing it to contract and move down. The passive processes of respiration proceed from there.

13. Students are usually familiar with hyperventilation and its link to anxiety. Explain the mechanism by which breathing into a paper bag acts to raise the CO2 levels, thus reversing the symptoms (in the textbook, see Homeostatic Imbalance 13.12 on p. 450). Note that another, often preferred, method to reverse symptoms of hyperventilation is to have the individual breathe through only one nostril with the mouth closed until normal breathing is restored.

Key point: Hyperventilation results in lowered CO2 levels. Immediate treatment is aimed at restoring the CO2 levels, followed by determination of the underlying cause.

14. Present an overview of chronic obstructive pulmonary disease (COPD), and differentiate between asthma, emphysema, and chronic bronchitis. Point out that with emphysema, the respiratory center is sensitive to changes in oxygen instead of carbon dioxide. For this reason, it is wise not to administer high concentrations of oxygen to people with emphysema because doing so could result in forced apnea.

Key point: These conditions have many similarities, as well as key differences. Emphasize the role of cigarette smoking in all of these conditions.

15. Explain the relationship of surfactant to lung expansion in infants. Discuss the results of incompletely developed lungs in premature infants, resulting in infant respiratory distress syndrome (IRDS).

Key point: Surfactant decreases surface tension, thus allowing alveoli to stay expanded and preventing lung collapse. Surfactant production is usually at a desirable level in a 32to 36-week fetus. Infants born prior to this time often suffer from IRDS and must be maintained on a ventilator until adequate surfactant levels are achieved. Surfactant pro145 INSTRUCTOR GUIDE FOR ESSENTIALS OF HUMAN ANATOMY & PHYSIOLOGY, 13e ..

duction can be stimulated by administration of a glucocorticoid one to two days prior to a preterm birth, and synthetic surfactant can be given to patients suffering from respiratory distress syndrome.

16. Explain the use of bronchodilators to treat asthma, and show how a severe asthma attack can be fatal.

Key point: Stress the importance of the muscles in the respiratory system for keeping the airway open.

17. Discuss the importance of prompt response when CPR is needed to keep oxygen moving throughout the body.

Key point: Reemphasize the need of the brain for oxygen, and how quickly brain tissue dies when oxygen is absent.

18. Describe lung cancer, including its link with smoking, and also how tumors frequently appear in the lungs during metastasis.

Key point: Students are usually aware that smoking can lead to lung cancer, but often they do not understand why many cancers metastasize to the lungs.

19. Discuss the symptoms, causes, and risk factors of snoring.

Key point: Snoring is the harsh sound due to a breathing obstruction while sleeping. It can be caused by a low, thick, soft palate; deviated nasal septum; or enlarged tonsils, which can obstruct the airway. Lifestyle causes include being overweight or drinking large amounts of alcohol before sleeping. In addition, snoring can be associated with obstructive sleep apnea. Because lifestyle causes can be prevented or reversed, it is important to discuss the importance of good lifestyle choices with students.

20. Explain the nonrespiratory movements of the respiratory system including coughing, yawning, hiccupping, and laughing.

Key point: Students are frequently interested in learning what causes these nonrespiratory movements.

Classroom Demonstrations and Student Activities Classroom Demonstrations 1. Use a dissectible human torso model to demonstrate the location of the respiratory organs. Discuss with students which structures are considered conducting zone structures, as well as where the respiratory structures can be found in the lungs.

2. Use a cross-sectional head model or torso model to demonstrate how the oropharynx and nasopharynx are common passageways for both food and air, and they are where food and air consequently travel. Talk about the importance of the soft palate, uvula, and epiglottis for creating barriers between the digestive and respiratory systems.

3. Demonstrate inspiration and expiration through exaggerated, deep breathing. Have students follow suit, placing their hands on the lateral areas of their rib cages to feel the volume changes.

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4. Show an anatomical model of alveoli surrounded by capillaries and an actual micrograph of the respiratory membrane, and discuss the site of connection between the respiratory and circulatory systems.

5. Demonstrate the Heimlich maneuver for adults (on self and on another individual) as a technique for removing a foreign body, such as aspirated food, from the trachea or pharynx. Discuss also what is done to alleviate choking in infants and toddlers.

6. Bring in a nebulizer and describe its uses in the treatment of asthma.

7. Demonstrate the cohesive effect that exists between the two pleural layers by putting a drop of water on a glass slide and then covering it with a second slide. Show that the slides easily move from side to side but are difficult to pull apart directly.

8. Use an articulated and disarticulated skull to show the location of the sinuses, as well as the cribriform plate where olfactory nerves pass through, as a good tie-back into Chapter 8 (Special Senses).

9. Invite a speaker (technician or physician) from a sleep-testing facility to describe the tests/sleep studies done to assess obstructive sleep apnea.

10. Use a “model lung” consisting of a bell jar with balloon “lungs” and a rubber “diaphragm” to illustrate the fact that volume changes in the thorax lead to the flow of gases in and out of the lungs during breathing.

11. Obtain a pair of bellows to alternatively show the relationship between volume and pressure for gas exchange.

12. Show prepared slides or diagrams of healthy lung tissue and lung tissue from patients who died from emphysema or lung cancer.

13. Show preserved specimens of diseased lungs that exhibit signs of COPD, emphysema, cancer, or pulmonary embolism.

14. Demonstrate how vocal cords function, using rubber bands as examples. Demonstrate how pitch is changed in the vocal cords by shortening or lengthening the rubber bands.

Also, show a video of a laryngoscopy to show how the vocal cords vibrate with differential pitch production, and discuss how the vibrations are visualized with assistance from a strobe light. (2006, 2 min., www.youtube.com/watch?v=iYpDwhpILkQ).

15. Discuss altitude-induced illnesses—how they occur, and their consequences. A link to the PBS Nova DVD available for purchase can be found here, along with classroom discussion resources: www.pbs.org/wgbh/nova/denali.

16. Have a respiratory therapist talk about his/her job responsibilities and some common issues that are observed with patients.

Student Activities 1. Prior to the beginning of lecture on the respiratory system, hand out a small straw, like those used as stir sticks, to each student. Ask them to breathe through the straw while you begin the lecture. After a few minutes, ask the students to describe the feelings they have from inadequate oxygen intake and relate those feelings to the way that a person with emphysema feels constantly.

2. Provide stethoscopes so that students can auscultate respiratory sounds over various regions of a classmate’s thorax. Define some of the usual breath sounds (wheezing, rales, 147 INSTRUCTOR GUIDE FOR ESSENTIALS OF HUMAN ANATOMY & PHYSIOLOGY, 13e ..

rhonchi) found in patients suffering from various respiratory conditions, such as asthma and chronic bronchitis; have students listen to recorded examples and then listen to their classmates breathing to detect any abnormal sounds.

3. Obtain several incentive spirometers so students can practice the technique of inhaling while moving the Ping-Pong ball up the cylinder. Explain that this is significantly more difficult following abdominal surgery or general anesthesia. Also have students measure their respiratory volumes, including tidal volume and vital capacity.

4. Have students in class use a spirometer and determine within the class if there are any differences in respiratory volumes due to sex differences, age differences, height differences, weight differences, or smoking preferences. Compare your results to the reference chart from the Centers for Disease Control and Prevention (CDC) found here: www.cdc.gov/niosh/topics/spirometry/refcalculator.html. As the second part of the experiment, have students do jumping jacks for a minute and test their lung capacity again.

Have students compare their values at rest and after exercise.

5. A simple “spirometer” can be made with tubing, a beaker or graduated cylinder, and a plastic tub filled with water. Tip over the beaker or graduated cylinder in water to fill it, and keep it upside down in the water. Have students take a deep breath and exhale through the tube (1) normally, and then, in the same “breath,” (2) forcibly to displace the water with the exhaled air. Students can mark the two levels of water remaining to measure the expiratory reserve volume.

6. Provide straws, beakers of water, and pH paper (or a pH-change color indicator such as bromothymol blue or phenolphthalein). Have students use the straws to blow into the water in the beakers. (Emphasize to the students that they must not suck in the liquid!) Because exhaled air contains substantially more carbon dioxide than does inhaled air, they will be adding carbon dioxide to the water, which will cause it to become acidic. Have them measure the pH of water at intervals to follow the change in pH; for a quicker experiment, place either color indicator initially in the water, then have students blow into the water with the straw and observe the color change. Discuss the implications of the color change with the students.

7. Play PBS Nova: How the Body Responds to Exercise video clip at ca.pbslearningmedia.org/resource/oer08.sci.life.reg.exercise/how-the-body-responds-toexercise and do the suggested activities found at www.pbs.org/wgbh/nova/education/body/body-responds-exercise.html for a good tie-in to the cardiovascular system, mitochondria function, and metabolism.

8. When discussing the importance of surfactant in aiding lung inflation, ask students to blow up balloons that are dry inside versus balloons that are wet inside. The surface tension of the water makes it difficult to inflate the balloon.

9. Assign students the task of researching the latest information on sudden infant death syndrome (SIDS) and the relationship to the respiratory system. Have students come to class prepared to discuss their findings.

10. Assign students the task of researching cigarette smoking and its respiratory sequelae, including lung cancer and emphysema. Have them include the latest research on the effects of secondhand smoke in children, including asthma.

11. Have students breathe into a clear sandwich-size plastic bag. Have the students record for each other the number of breaths that they can take using the same air until it is uncom..

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fortable, with normal breathing. Alternatively, the duration of breathing can be recorded.

Also have students observe their breaths in a bag. Discuss with the students why moisture can be observed in the bag, as well as the relative temperature (warmer versus colder) of their breaths as compared to the room temperature.

12. Have students investigate the effects of air pollution on the respiratory system structures.

13. Have students investigate safety of electronic cigarettes in current research findings.

Media See page 164 for a listing of media resources.

1. Circulation, Respiration, and Breathing (FHS: 20 min., 2001, VHS, DVD, 3-year streaming webcast). This program explains the complementary functions of the circulatory and respiratory systems that work together to meet the body’s energy needs.

2. Respiratory System Introduction (Khan Academy, 2012, www.khanacademy.org/science/health-and-medicine/respiratory-system#respiratorysystem-introduction). Videos, tutorials, and self-quiz on the respiratory system.

3. Lung Disease and Respiratory Health Center (WebMD: 2016, www.webmd.com/lung/video/video-index). A repository of videos about various respiratory conditions.

4. Respiratory System Parts 1 and 2 (Crash Course: 20 min., 2015, thecrashcourse.com/courses/anatomy). The structures of the respiratory system and the process of pulmonary ventilation are discussed.

5. Lung and Bronchus Cancer: Did You Know? (NCI: 4 min., 2017, www.youtube.com/watch?v=qsgMSB1WCQQ). A short video clip on lung cancer by the National Cancer Institute.

6. NOVA: Deadly Ascent (PBS: 56 min, 2006, DVD). Researchers delve into factors of altitude-induced illnesses in the context of their experiences on Mount McKinley, the highest mountain peak in North America.

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CHAPTER

14

The Digestive System and Body Metabolism

Chapter Summary The digestive system chapter is divided into two distinct parts. Part I delves into the anatomy and physiology of the digestive system. This portion is the easier of the two parts for students to learn, since students generally are fascinated by the workings TEACHING TIP of their digestive system. Part II deals with the nutritional and metabolic aspects of digestion. Because these biochemical conThe function of different members of the alimencepts are often difficult to visualize, as they are molecular pathtary canal should be disways, this is often the area students find most confusing. cussed for better student understanding. For examIn outlining digestive system anatomy, the author emphasizes ple, the mouth, stomach, the tubular structure of the alimentary canal, noting that it has and small intestine peropenings at both ends (like a hose). The organs of this canal, disform mechanical digestion through mastication, cussed in order of food travel through the GI tract, are the churning, and segmentamouth, pharynx, esophagus, stomach, small intestine, and large tion can be discussed. intestine. Each of these components is described in detail, and These three areas also are also areas of chemical examples of homeostatic imbalances are explained where pertidigestion as well, as salinent. A discussion of the accessory digestive organs—their locavary amylase begins tions and functions—is next and includes coverage of the chemical digestion in the mouth, lingual lipase and salivary glands, teeth, tongue, pancreas, liver, and gallbladder. gastric lipase begin lipid The overall general functions of the digestive system are prebreakdown in the stomsented next and include ingestion, propulsion, mechanical digesach, while pepsin begins protein digestion in the tion, chemical digestion, absorption, and defecation; each of stomach, and the pancrethese activities is discussed in relation to the organs in which atic and intestinal brush they occur. border enzymes finish chemical digestion in the In Part II, the basics of nutrition are presented. First, current duodenum of the small dietary recommendations are discussed. Once foods are digested intestine. and absorbed into the bloodstream, the next step involves utilization of the nutrients obtained. The major nutrients include carbohydrates, lipids, proteins, vitamins, and minerals. Metabolism is a term that describes all of the chemical reactions in the body, comprising two separate processes: catabolism (breakdown/deconstructing reactions) and anabolism (building up/constructing reactions). Major nutrients are both catabolized for energy and anabolized for body structure in metabolism.

Specifically discussed in this chapter are the processes of carbohydrate metabolism and production of adenosine triphosphate (ATP) for energy, fat metabolism and storage (as a reserve potential energy source), and protein breakdown (provides amino acids for new protein construction). The role of the liver in metabolism is also presented, as are cholesterol metabolism and transport.

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The final section of this chapter explores the relationship between energy intake and energy output. Basal metabolic rate is compared with total metabolic rate. Processes involved in body temperature regulation are explained, and the most important developmental aspects are presented, from infancy to old age, as well as the major homeostatic imbalances at the different developmental periods.

Suggested Lecture Outline Part I: Anatomy and Physiology of the Digestive System (pp. 460–485) I. 14.1 Anatomy of the Digestive System (pp. 460–474) A. 14.1a Organs of the Alimentary Canal (pp. 461–470) 1. Mouth 2. Pharynx 3. Esophagus 4. Stomach 5. Small Intestine 6. Large Intestine B. 14.1b Accessory Digestive Organs (pp. 470–474) 1. Teeth 2. Salivary Glands 3. Pancreas 4. Liver and Gallbladder

II. 14.2 Functions of the Digestive System (pp. 474–485) A. 14.2a Overview of Gastrointestinal Processes and Controls (pp. 474–476) 1. Ingestion 2. Propulsion 3. Food Breakdown: Mechanical Breakdown 4. Food Breakdown: Digestion 5. Absorption 6. Defecation

MEDIA TIP The Poop Cure (PBS: 2 min., 2017). www.pbs.org/wgbh/nova/vid eo/can-poop-cure-aninfection/ A short video clip on fecal transplantation to combat antibiotic resistant bacterial infections such as Clostridium difficile, using bacterial flora. This can a be a springboard into discussing the importance of gut microbiota in various areas such as brain development and immunity, to tie-in previously learned organ systems to the digestive system.

B. 14.2b Activities Occurring in the Mouth, Pharynx, and Esophagus (pp. 476–478) 1. Food Ingestion and Breakdown 2. Food Propulsion—Swallowing and Peristalsis C. 14.2c Activities of the Stomach (pp. 478–480) 1. Food Breakdown 2. Food Propulsion D. 14.2d Activities of the Small Intestine (pp. 480–482) 1. Chyme Breakdown and Absorption 2. Chyme Propulsion E. 14.2e Activities of the Large Intestine (pp. 482–483) 1. Nutrient Breakdown and Absorption 2. Propulsion of Food Residue and Defecation 151

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F. 14.2f The Microbiota (pp. 483–485)

Part II: Nutrition and Metabolism (pp. 485–498) I. 14.3 Nutrition (pp. 485–488) A. 14.3a Dietary Recommendations (pp. 485–486) B. 14.3b Dietary Sources of the Major Nutrients (pp. 486–488) 1. Carbohydrates 2. Lipids 3. Proteins 4. Vitamins 5. Minerals

II. 14.4 Metabolism (pp. 488–498) A. 14.4a Carbohydrate, Fat, and Protein Metabolism in Body Cells (pp. 488–491) 1. Carbohydrate Metabolism 2. Fat Metabolism 3. Protein Metabolism B. 14.4b The Central Role of the Liver in Metabolism (pp. 491–494) 1. General Metabolic Functions 2. Cholesterol Metabolism and Transport C. 14.4c Body Energy Balance (pp. 494–498) 1. Regulation of Food Intake 2. Metabolic Rate and Body Heat Production a. Basal Metabolic Rate b. Total Metabolic Rate 3. Body Temperature Regulation a. Heat-Promoting Mechanisms b. Heat Loss Mechanisms

Part III: Developmental Aspects of the Digestive System and Metabolism (pp. 499–500, 502) Note: For a list of Key Terms for this chapter, please go to Mastering A&P > Study Area > Additional Study Tools > Key Terms > Chapter 14.

Learning Objectives 14-1 Name the organs of the alimentary canal and accessory digestive organs, and identify each on an appropriate diagram or model.

14-2 Identify the overall function of the digestive system as digestion and absorption of foodstuffs, and describe the general activities of each digestive system organ.

14-3 Explain how villi aid digestive processes in the small intestine.

14-4 List the accessory digestive organs, and describe the general function of each.

14-5 Name the deciduous and permanent teeth, and describe the basic anatomy of a tooth.

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14-7 Name the main digestive products of the pancreas and of the liver.

14-8 List and describe the six main activities of the digestive system.

14-9 Describe how foodstuffs in the digestive tract are mixed and moved along the tract.

14-10 Describe the function of local hormones in digestion.

14-11 List the major enzymes or enzyme groups involved in digestion, and name the foodstuffs on which they act.

14-12 Describe the mechanisms of swallowing, vomiting, and defecation.

14-13 Name the end products of protein, fat, and carbohydrate digestion.

14-14 Define microbiota, microbiome, and colitis.

14-15 Define nutrient and kilocalorie.

14-16 List the six nutrient categories. Note important dietary sources and their main cellular uses.

14-17 Define metabolism, anabolism, and catabolism.

14-18 Recognize the uses of carbohydrates, fats, and proteins in cell metabolism.

14-19 Describe the metabolic roles of the liver.

14-20 Explain the importance of energy balance in the body, and indicate consequences of energy imbalance.

14-21 List several factors that influence metabolic rate, and indicate each one’s effect.

14-22 Describe how body temperature is regulated.

14-23 Name important congenital disorders of the digestive system and significant inborn errors of metabolism.

14-24 Describe the effect of aging on the digestive system.

Resources for Teaching Online Discussion Board Topic: Homeostatic Imbalance—Hepatitis In the textbook on page 473, the Homeostatic Imbalance section describes hepatitis as an inflammation of the liver caused primarily by a viral infection from drinking contaminated water, or transmitted through blood through a transfusion or contaminated needle. Hepatitis can lead to jaundice or even cirrhosis. Engage your students by using the following discussion questions in lecture or by posting them to the discussion board on your course management system.

Discussion Questions 1. What are the three most common types of viral hepatitis and how is each transmitted?

2. What are the most recent trends in the transmission rates of these three types of viral hepatitis?

3. Which viral hepatitis types are preventable—that is, which ones have vaccines?

4. Why does hepatitis resolve in some individuals but remain a chronic infection in others?

What does current research show? Discuss some current findings on this subject.

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1. Hepatitis B, A, and C, in the order of new cases/year; however, hepatitis C has the highest total number of Americans with the disease, followed by hepatitis B. (Hepatitis A is more of an acute infection, while B and C are chronic diseases.) Hepatitis A is transmitted primarily through the fecal-oral route, either through person-to-person contact or through contaminated food ingestion. Hepatitis B is contracted through punctures in the skin or through mucous membranes—for example, contaminated needles, contact with blood or open sores of an infected person, sharing toothbrushes or razors, unprotected sex, and birth to an infected mother. Hepatitis C is more commonly contracted through contaminated needles and blood transfusions/organ transplants, although it is possible to contract it through contact with body fluids and mucous membranes.

2. According to figures produced by the CDC in 2014, there was a 25.8 percent decline in contraction of hepatitis A from 2010 to 2014; a decline of 11.9 percent for hepatitis B contraction in the same time frame; and for hepatitis C, an increase of 158.1 percent of reported cases. There is no vaccine available for the hepatitis C virus, which is considered an “emerging epidemic” due to increased injected drug use.

3. Vaccines are available for hepatitis A and B but not for hepatitis C. Because there are a number of different genotypes of hepatitis C, the virus can mutate quickly, and a good animal model system to study viral mechanisms in vivo is not present.

4. Some areas of research are the following: RNAi treatment for hepatitis B, and direct acting antiviral (DAA) treatment for hepatitis C.

Investigate Online Take learning a step further by searching for relevant research articles on the Web. Visit science websites, such as those listed below, and begin by searching for key terms such as hepatitis A, hepatitis B, hepatitis C, hepatitis treatment, acute hepatitis, chronic hepatitis, and autoimmune hepatitis and see how what you’re learning in the course applies to science and medicine today. www.sciencedaily.com www.scientificamerican.com www.the-scientist.com www.ncbi.nlm.nih.gov/pubmed www.nature.com/subjects/hepatitis

Study Tips Direct students to the Study Tips feature located in the front of the book.

Mastering A&P Numerous items from Mastering A&P can be demonstrated in class, assigned as homework, or encouraged as study materials. These include practice tests and quizzes, animations and videos, Interactive Physiology (IP), Dynamic Study Modules, Audio Journeys, Practice Anatomy Lab (PAL), PhysioEx, flashcards, glossary, key terms, and more.

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Interactive Physiology (IP) The following sections of Interactive Physiology are relevant to this chapter: Digestive System IP Anatomy Review Animation: Digestive IP Animation: Control of the Digestive System IP Animation: Digestive System Secretion IP Animation: Enzymatic Digestion and Absorption

PhysioEx10.0 The following sections of PhysioEx10.0 are relevant to this chapter:

Videos of PhysioEx Lab Experiments: BMR Measurement

Exercise 8: Chemical and Physical Processes of Digestion

Animations and Videos The following animations and videos are relevant to this chapter:

Bio Flix > Cellular Respiration

Bone and Dissection Videos > Cat Dissection > Digestive Structures of the Head; The Peritoneum; Structures that Pass through Mesenteries

Bone and Dissection Videos > Fetal Pig Dissection > Organs of the Digestive System

Practice Anatomy Lab (PAL)3.1: Including Mobile Flashcards The following sections of PAL3.1 are relevant to this chapter:

Human Cadaver > Digestive System

Anatomical Models > Digestive System

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Histology > Digestive System

Cat > Digestive System

Fetal Pig > Digestive System

Additional Study Tools The following video is relevant to this chapter:

Focus on Careers > Dental Hygienist

Lecture Hints 1. Discuss how the alimentary canal is actually the “exterior” of the body and that food does not actually enter the body cells prior to absorption.

Key point: Students are surprised to learn that although they ingest food into their body, it is not considered to be inside the body until absorption in the small intestine. Use this opportunity to discuss the close relationship between the digestive and lymphatic systems (MALT and GALT tissue) to protect the interior of the body from pathogens.

2. The secretions made in various parts of the alimentary canal, the salivary glands, the liver, and the pancreas are derived from blood plasma, just as we saw with lymph fluid.

Throughout the course of lectures on digestion, keep a running tab of the volume of plasma used to generate fluids for digestion.

Key point: This will help students appreciate the role of the large intestine in reabsorbing water and will help them understand the life-threatening consequences of prolonged diarrhea, especially in children.

3. Note that the villi, microvilli, and circular folds of the small intestine are key to major amounts of absorption due to efficient structural modifications that increase surface area in a limited amount of space, whereas the mucosa of the stomach lining produces large amounts of mucus that protect the stomach wall from digestion by its own juices. Emphasize the structural modifications in each area of the GI tract that lead to optimum digestion and absorption.

Key point: Each area of the GI tract is modified to perform specific digestive functions, such as absorption of nutrients, absorption of water, and breakdown of carbohydrates, proteins, or fats. Emphasize the distinction between villi and microvilli structure in relation to the cell versus tissue.

4. Discuss celiac disease and its effect on absorption of nutrients.

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this type of malnutrition are diarrhea and weight loss. In undiagnosed children, failure-tothrive syndrome may be observed. Subsequent susceptibility to GI cancers may also result if left untreated. Celiac disease is an autoimmune disease in which the immune system attacks the lamina propria of the small intestine, triggered by gluten protein (found in wheat, barley, rye, and others). By avoiding foods with gluten, the autoimmune response disappears.

5. Emphasize that the rugae of the gastric mucosa allow the stomach to collapse in on itself or stretch to accommodate a large meal as the need arises; compare this to the esophagus, which similarly adapts as well. Contrast with the plicae circulares of the small intestine.

Key point: This is an example of complementary structure and function; and though they appear similar in structure, the modifications can have different functions in different parts of the alimentary canal The rugae allow for space conservation, while the plicae circulares increase surface area and time of contact for optimal nutrient absorption.

6. While discussing each section of the alimentary canal, emphasize which specific nutrients are being digested along the way and list the digestive enzymes involved in the chemical digestion of each nutrient. At the end of the presentation, review the major areas of carbohydrate, protein, and lipid digestion and the enzymes involved in each.

Key point: It is important for students to realize that breakdown (mechanical and chemical) of nutrients occurs along the entire alimentary canal, and that each region has its specialty. The importance of the small intestine in finishing up chemical digestion with its own enzymes, as well as with the pancreatic enzymes emptied into the duodenum (along with bile from the liver and gallbladder that emulsify fats), should be emphasized.

7. Emphasize location and structure of the incisors, canine, premolars, and molars.

Key point: This reinforces the idea of complementarity of structure and function, even at the level of the teeth.

8. Explain the diet modifications that need to occur after gallbladder surgery. Discuss cholelithiasis (gallstones) and the current treatment options for this condition.

Key point: Gallstones arise when bile is stored too long or becomes excessively concentrated. Treatment options include surgical removal and lithotripsy.

9. Explain the various types and causes of jaundice.

Key point: Jaundice can be pathologic, as with hepatitis; nonpathologic, as with jaundice of newborns; or obstructive, as with cholelithiasis. Understanding this condition as a sign rather than a disease helps students visualize the physiological processes involved.

10. Discuss cirrhosis and its causes.

Key point: Students often consider cirrhosis to be a direct manifestation of alcoholism and are surprised to learn that it has numerous causes, including chronic hepatitis, malnutrition, and heredity. Alcoholism is also associated with dehydration.

11. In discussing peristalsis, point out that astronauts are able to swallow in any position, and that although gravity helps move things through the alimentary canal, the process continues even in the absence of gravity.

Key point: Peristalsis occurs in many regions of the alimentary canal and is a major factor in the movement of chyme through the system.

12. Explain the digestive implications of cleft lip and palate in the sucking reflex.

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Key point: Although this condition is readily treated in the United States, it continues to be of major significance in third-world countries where it often goes untreated, with serious nutritional implications.

13. Discuss how ATP is generated in oxygenated and underoxygenated conditions. Be sure to allocate extra time to the production of ATP through the various processes, including the Krebs cycle, glycolysis, and the electron transport chain.

Key point: These are complex processes that require extra effort in presentation, but it is important for students to grasp the correlation between the metabolic processes of catabolism and anabolism. This discussion also shows the relevance of learning chemistry to understand biological processes and ties in concepts learned in Chapter 2.

14. Reinforce the concepts learned in the cardiovascular chapter about the benefits and dangers of cholesterol. Review HDLs and LDLs. Key point: Both HDLs and LDLs are necessary components of steroid hormones and vitamin D. It is their relative ratio in the blood that is the determining factor in whether they have harmful side effects.

15. Discuss the importance of maintaining low pH in the stomach and then explain how other parts of the digestive tract neutralize the acidic pH that leaves this region. Include a discussion of heartburn and ulcers. Also discuss how the small intestine is not acidic and how this is accomplished.

Key point: Revisiting the pH concept at this point allows the instructor to reemphasize the proper functioning of enzymes and proteins in different parts of the body.

16. Explain how gastric bypass and lap band surgery can be used to treat obesity. Discuss the nutritional and physiological implications of these surgeries.

Key point: With obesity being so much more prevalent, students are curious to learn about the effects of these procedures.

17. Discuss the appendix and appendicitis and implications if symptoms are ignored.

Key point: Although previously thought as a vestigial organ with no known function, current research suggests that there is a purpose for the appendix. First, there is immune tissue in the area, and some lymphocytes are matured in the appendix. Additionally, the appendix is thought to be a reservoir/holding tank for commensal bacteria (good bacteria) in the gut. Appendicitis is an inflammation of the appendix, which usually becomes filled with pus. Some symptoms include, among others, pain in the lower right abdomen that increases low-grade fever, pain that increases when coughing or walking, nausea or vomiting, low-grade fever, and constipation or diarrhea. If not addressed, the appendix can burst and cause peritonitis, which is life-threatening. Discuss how appendicitis can be caused; this is a good tie-in to the immune system.

18. Remind students how the pancreas functions as an exocrine gland in the digestive system and an endocrine gland for the endocrine system.

Key point: The pancreas performs both endocrine and exocrine gland functions, and this is a great example of how the body systems work with one another. In particular, it is important to convey to the students that the endocrine function of the pancreas and its regulation of glucose levels are important in the digestive system in terms of metabolic processes.

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19. Describe the various types of cancer associated with the digestive system, including their prognoses and treatment options.

Key point: While some research into certain cancers (e.g., colon cancer) has led to large strides in terms of treatment, others cancers, such as pancreatic and esophageal cancers, still have very poor prognoses.

20. Describe and discuss irritable bowel syndrome (IBS), Crohn’s disease, and acid reflux disease.

Key point: Students are usually familiar with these conditions and can relate personal experiences to treatment options.

21. Discuss the consequences of “high colonics” or “colonic hydrotherapy” treatments.

Key point: Enemas to cleanse the large intestine have grown in popularity. Discuss the implications on acid-base, water, and enteric bacteria balance in the large intestine, as well as the risks of using improperly cleaned equipment.

22. A topic relevant to both the digestive and immune systems is the discovery of Helicobacter pylori as a cause of gastritis and peptic ulcers. Discuss the Nobel Prize–winning discovery and treatment implications.

Key point: Ulcers were previously thought to be caused by stress, acidic, or spicy food.

Although these factors can exacerbate ulcers, according to the CDC up to 80 percent of gastric ulcers and more than 90 percent of duodenal ulcers have been found to be caused by the bacterium Helicobacter pylori. Another common culprit is intake of NSAIDs. Antibacterials to combat the H. pylori infection are administered as treatment.

23. Describe the makeup of the microbiota, or normal flora, and note its importance in maintaining a healthy gut. Discuss the effect of antibiotics on the microbiota, including the potential for C. difficile colonization of the gut.

Key point: Many strains of C. difficile are resistant to antibiotics. Fecal microbial transplant (FMT) has a cure rate over 90 percent for treatment of C. difficile strains that are resistant to antibiotics. www.hopkinsmedicine.org/johns-hopkins-childrens-center/whatwe-treat/specialties/gastroenterology-hepatology-nutrition/procedures/fecal-microbialtransplantation.html

Classroom Demonstrations and Student Activities Classroom Demonstrations 1. Demonstrate how antacids work to raise pH of acidic solutions by measuring with pH paper, and relate this to what they do to relieve heartburn.

2. Discuss the mechanisms of proton pump inhibitors and H2 blockers to reduce acid production in the stomach.

3. Use a dissectible human torso model to demonstrate the pathway of food digestion through the alimentary canal organs. Point out the accessory organs and structures.

4. Use a human skull or jaw model to introduce the different tooth shapes, names, and numbers. If a sectioned tooth is available, share this with the students.

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5. Rennin will turn casein (milk protein) into a curd in an infant’s stomach; the liquid that is left is called whey. Adding some rennin, available from biological supply companies, to milk will quickly demonstrate this point. Ask students why they think this might be beneficial in infants.

6. The digestive function of the liver is to produce bile. With the students’ assistance, compile a list of the liver’s other functions as studied so far, then introduce new functions related to metabolism. Tie in such functions as thrombopoetin production, which shows the connection to endocrine and cardiovascular system functioning.

7. Demonstrate the emulsifying action of bile. First mix oil and water together and allow the layers to separate. Then add bile salts and shake vigorously. Point out that the layer of oil has been dispersed into hundreds of tiny fatty spheres by the action of the bile salts. An alternative is to mix oil and water in a container, then add a couple drops of liquid dishwasher detergent to demonstrate emulsification of the oil.

8. Borrow a specimen jar containing gallstones from a local GI surgeon to enhance your presentation of why gallstones form and why they are painful.

9. Using molecular models of carbohydrate, fat, and protein molecules, demonstrate the processes of dehydration synthesis and hydrolysis in the process of metabolism and relate back to concepts learned in Chapter 2.

10. Invite a guest speaker from the local dental hygienists’ organization to come to class and present information on the benefits of good oral health and why flossing daily, in addition to regular brushing with fluoride, is important. Have the speaker also demonstrate proper brushing technique.

11. Bring in a glucometer and discuss what blood glucose levels you would expect to find before and after a meal. Also, in the same discussion, show micrographs of pancreatic cells stained for glucagon before and after a meal.

12. Demonstrate the process of segmentation and peristalsis. This can be done with a balloon with Play-Doh placed inside the top, moving the Play-Doh down the balloon to mimic peristalsis; for segmentation, a balloon can be partially filled with water, and each end can be squeezed alternatively to mimic the mixing motion of segmentation.

13. Bring in nutritionists/registered dieticians to compare and contrast different diet options (low carb, low fat, etc.) for losing and maintaining weight.

14. Show prepared slides of fecal material that have normal bacterial flora from different regions of the digestive tract.

Student Activities 1. Point to digestive system organs in a torso model and ask students to identify whether chemical and/or mechanical digestion takes place; the nutrient that will be extracted after digestion; and, if chemical digestion, what enzymes are being used? If mechanical digestion, is it through segmentation or churning or another method?

2. Bring bread to class and have the students each chew a piece. Ask them how it tastes when it has been chewed for a long time before it is swallowed. (It should taste sweet due to the presence of salivary amylase.)

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3. Have students place iodine drops on cornstarch or potato starch. The color indicator will be black on contact with starch. In a test tube with some starch, have students spit into the test tube. Have students add iodine at the end of class and compare colors. Alternatively, have students heat their tubes in a water bath to speed up the reaction and then add iodine at the end. The iodine should remain yellowish, or if in midprocess, less dark than starch alone, as the amylase in the saliva has broken down the starch to simpler sugars.

4. Have students research why chocolate milk can help postworkout recovery.

5. Have students calculate their total caloric intake over a 24-hour period by using a simple caloric guide (obtainable in most drugstores). Then have them analyze their diet with an eye to what improvements could be made to their eating habits.

6. When discussing the swallowing mechanism, have students place their hands on their larynx so that they can feel it rise when they swallow. Remind them of the function of the epiglottis. Provide small cups of water as needed.

7. Have students research ulcers, diverticuli, intestinal polyps, and hemorrhoids. Discuss the signs and symptoms of each, focusing on the presence or absence of blood in stools.

8. Have students research eating disorders such as anorexia and bulimia, and discuss the nutritional and physiological implications of these behavioral diseases.

9. Have students research and discuss the validity of benefits on autism symptoms of a glutenfree, casein-free (GFCF) diet.

10. Show the film Super Size Me and assign your students a paper covering the issues and debates raised by this movie. For example, they could discuss whether they felt that the movie was an unbiased presentation of the obesity/fast food issue or propaganda against big-money corporations, and why. Another possible topic for a paper is a discussion on who should bear the burden of responsibility for obesity and its health effects and costs.

Why or why not? The students could also discuss the likelihood of eating a more healthful diet and the reasoning for it. Additional topics covering issues raised by this movie can be found on the Internet.

11. Have students watch the film Forks over Knives and have them analyze the diet proposed in the film using the concepts covered in the nutrition portion of the chapter.

12. Have students research probiotics and how bacterial flora can contribute to homeostasis.

13. Have students work together to create and complete summary tables for (1) which of the six digestive system functions occur within each of the organs along the aligmentary canal (e.g., stomach–propulsion, mechanical breakdown, chemical digestion, absorption) and (2) the actions of the major digestive enzymes including their source, site of action, and substrates/products (e.g., salivary amylase produced by the salivary glands, acts in the mouth to break down carbohydrates).

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Media See page 164 for a listing of media resources.

1. An End to Ulcers: A Journey of Discovery (FHS: 57 min., 1998, VHS, DVD). This program outlines the history of diagnosis and treatment of ulcers and the extraordinary discovery that H. pylori is the true cause of most peptic ulcers.

2. What’s Wrong with What We Eat? (TED: 130 min., 2010, www.ted.com/playlists/75/what_s_wrong_with_what_we_eat). A video playlist of 9 short videos examining cultural and societal perspectives on food.

3. Managing Cholesterol (FHS: 28 min., 2005, VHS, DVD, 3-year streaming webcast). Illustrates the effects of LDL and HDL cholesterol on the heart and circulatory system and includes three varied case studies and expert commentary.

4. The Anatomy of Digestion (FHS: 51 min., 2005, DVD, 3-year streaming webcast). Gunther von Hagens takes the viewer step-by-step through each process of the digestive system and explains such concepts as burps, heartburn, and ulcers.

5. Food and Digestion (FHS: 27 min., 2004, VHS, DVD, 3-year streaming webcast). This program features graphics and simple experiments to illustrate how the body absorbs nutrients from different types of food and differentiates between mechanical and chemical digestion.

6. The Digestive System Parts 1, 2, and 3 (Crash Course: 32 min., 2015, thecrashcourse.com/courses/anatomy). These videos discuss the structure and function of the digestive system.

7. The Digestive System (IM: 16 min., 2005, DVD). This video demonstrates how the digestive system breaks down food into usable form.

8. Nutrition and Metabolism Parts 1 and 2 (Crash Course: 21 min., 2015, thecrashcourse.com/courses/anatomy). Nutrients, general overview of anabolic and catabolic processes, cellular respiration, and gluconeogenesis are discussed.

9. MyPlate, MyWins Video Series (USDA: 2016, www.choosemyplate.gov/videos). Series of video vignettes on healthy eating solutions and lifestyles produced by the U.S. Department of Agriculture (USDA).

10. Dying to Be Thin (PBS: 54 min., 2000, www.pbs.org/wgbh/nova/body/dying-to-bethin.html). This video discusses anorexia, bulimia, and other eating disorders.

11. Lorenzo’s Oil (129 min., 1992, VHS, DVD). A film that documents the real-life story of Lorenzo Odone, who has a rare myelin-degenerating terminal disease called adrenoleukodystrophy (ALD), and his parents (Augusto and Michaela), who collide with doctors, scientists, and support groups in their quest to develop an oil from the combination of two fats, extracted from olive and rapeseed oil, to prevent the body’s production of verylong-chain fatty acids whose buildup leads to demyelination. See http://www.myelin.org for more information.

12. What’s New about Vitamins and Phytonutrients (FHS: 20 min., 2005, VHS, DVD). Explains the importance of plant-based nutrients in wellness and the prevention of cancer and heart disease, along with a discussion on the consequences of heavy use of vitamin supplements.

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13. Super Size Me (100 min., 2004, VHS, DVD). Documents filmmaker Morgan Spurlock’s investigation of the American obesity epidemic by interviewing experts and laypersons nationwide on the perils of excessive fast-food consumption and by anatomically, physiologically, and psychologically documenting his personal deteriorating health while on a “McDonald’s only” eating binge for 30 consecutive days. This documentary won the award for Best Director at the prestigious Sundance Film Festival in January 2004 by investigating corporate versus consumer responsibility for the rising obesity level in American youth and adults, nutritional education, school lunch programs, and how and why Americans are literally eating themselves to death.

14. Upper gastrointestinal endoscopy technique video (7 min., 2014) Video tour presents endoscopy technique. www.youtube.com/watch?v=DUVDKoKSEkU 15. Fecal Microbial Transplantation (4 min., 2014) Overview of FMT presented by the Mayo Clinic. www.youtube.com/watch?v=Awn3haOpfcI

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15

The Urinary System

Chapter Summary The kidneys, as described in the chapter, “are perfect examples of homeostatic organs” that perform a wide variety of functions. They filter fluid from the bloodstream and process the filtrate. They excrete nitrogenous wastes and excess ions, rid the body of drugs and toxins, and retain needed ions and nutrients. They manufacture urine and regulate the volume and chemical makeup of blood. They balance water and salts, as well as acids and bases. They also convert vitamin D to its active form and produce hormones that function to regulate blood pressure and stimulate red blood cell (RBC) production. This chapter outlines each of these functions and explains the homeostatic link between them.

The first section of this chapter begins by discussing the anatomy of the kidney. Each kidney has a structure similar to its neighbors, the adrenal glands, in that there is an outer cortex and an inner medulla. Blood supply to the kidneys is extensive—one-quarter of the total blood supply of the body goes through the kidneys each minute. The structural and functional units of the kidneys are the nephrons, consisting of the glomerulus and the renal tubule. Glomeruli are high-pressure capillaries that act as filters to perform the passive process of filtration, while reabsorption and secretion are performed by the renal tubules.

Urine formation is a result of all three of these processes. Urine has distinct characteristics, and it is explained that many diseases manifest themselves in abnormal urine composition, thus emphasizing the value of routine urinalysis.

The next section of the chapter outlines the structure and function of the other organs of the urinary system (e.g., the ureters, urinary bladder, and urethra). Micturition is explained as the act of emptying the bladder, also known as voiding, or urination. The kidney’s role in fluid and electrolyte balance in the blood is explored next, and the link between water and salt is explained. The kidneys also have a role in maintaining the acid-base balance of blood. Of the three mechanisms for regulating blood pH—blood buffers, respiratory system controls, and renal mechanisms—the kidney functions, or renal mechanisms, are slower but more potent than other mechanisms. Finally, the chapter explores the development of the urinary system organs, as well as the effects of aging. Several examples of homeostatic imbalance of the urinary system also are presented.

Suggested Lecture Outline I. 15.1 Kidneys (pp. 512–520) A. 15.1a Location and Structure (pp. 512–513) 1. Kidney Structure 2. Blood Supply B. 15.2b Nephrons (pp. 513–516)

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C. 15.2c Urine Formation and Characteristics (pp. 516–520) 1. Glomerular Filtration 2. Tubular Reabsorption 3. Tubular Secretion 4. Nitrogenous Wastes 5. Characteristics of Urine

TEACHING TIP When discussing filtration, tubular reabsorption, and tubular secretion, an analogy to cleaning closets can be made. One effective way to clean out a closet is to remove everything (filtration), and then put back into the closet what you want to keep (reabsorption). This way, because there is limited room in the closet, you have to use a more critical eye in selecting what to keep and what to throw away; what is not needed, and is thrown away permanently, represents secretion.

The concept of urine formation can be difficult for the students; start out your discussion with an overview using the above analogy, then get into the specifics of location of filtration, reabsorption, and secretion in a nephron, and what substances go in and out of each area, using Figure 15.5.

II. 15.2 Ureters, Urinary Bladder, and Urethra (pp.

520–524) A. 15.2a Ureters (p. 520) B. 15.2b Urinary Bladder (pp. 521–522) C. 15.2c Urethra (p. 522) D. 15.2d Micturition (pp. 522, 524)

III. 15.3 Fluid, Electrolyte, and Acid-Base Balance (pp.

524–531) A. 15.3a Maintaining Water Balance of Blood (pp. 524– 527) 1. Body Fluids and Fluid Compartments 2. The Link between Water and Electrolytes 3. Regulation of Water Intake and Output B. 15.3b Maintaining Electrolyte Balance (pp. 527–529) C. 15.3c Maintaining Acid-Base Balance of Blood (pp.

529–531) 1. Blood Buffers 2. Respiratory Mechanisms 3. Renal Mechanisms

IV. 15.4 Developmental Aspects of the Urinary System (pp. 531–533) Note: For a list of Key Terms for this chapter, please go to Mastering A&P > Study Area > Additional Study Tools > Key Terms > Chapter 15.

MEDIA TIP Is it bad to hold your pee?

(TedEd, 4 min., 2016, ed.ted.com/lessons/is-itbad-to-hold-your-pee-hebashaheed). Video about the process of micturition and accompanying self-quiz that can be watched individually or in class.

Learning Objectives 15-1 Describe the location of the kidneys in the body.

15-2 Identify the following regions of a kidney (longitudinal section): hilum, cortex, medulla, medullary pyramids, calyces, pelvis, and renal columns.

15-3 Recognize that the nephron is the structural and functional unit of the kidney, and describe its anatomy.

15-4 Describe the process of urine formation, identifying the areas of the nephron that are responsible for filtration, reabsorption, and secretion.

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15-5 Describe the function of the kidneys in excretion of nitrogen-containing wastes.

15-6 Define anuria and oliguria.

15-7 Describe the composition of normal urine.

15-8 List abnormal urinary components.

15-9 Describe the general structure and function of the ureters, urinary bladder, and urethra.

15-10 Compare the course and length of the male urethra to that of the female.

15-11 Define micturition.

15-12 Describe the difference in control of the external and internal urethral sphincters.

15-13 Name and localize the three main fluid compartments of the body.

15-14 Explain the role of antidiuretic hormone (ADH) in the regulation of water balance by the kidney.

15-15 Explain the role of aldosterone in sodium ion and potassium ion balance of the blood.

15-16 Define diuresis and polyuria.

15-17 Compare and contrast the relative speed of buffers, the respiratory system, and the kidneys in maintaining the acid-base balance of the blood.

15-18 Describe three common congenital problems of the urinary system.

15-19 Describe the effect of aging on urinary system functioning.

Resources for Teaching Online Discussion Board Topic: Homeostatic Imbalance—Polycystic Kidney Disease In the textbook on page 532, the Homeostatic Imbalance section discusses polycystic kidney disease, which is a genetic disease that affects the kidneys, where one or both kidneys enlarge and develop noncancerous, fluid-filled, blister-like sacs called cysts. These cysts obstruct urine drainage, which can lead to kidney complications. Engage your students by using the following discussion questions in lecture or by posting them to the discussion board on your course management system.

Discussion Questions 1. What are the common symptoms associated with polycystic kidney disease (PKD)?

2. What are the two genetic classifications of PKD? Do they differ in any way?

3. How is PKD diagnosed?

4. What are some of the complications that arise from PKD?

Potential Student Responses: 1. Common symptoms include high blood pressure, blood in urine, frequent urination, urinary tract or kidney infections, back or side pain due to the enlarged kidney(s), headache, kidney stones, and kidney failure.

2. Autosomal dominant PKD and autosomal recessive PKD. The signs and symptoms are the same, but the age of usual onset differs. Autosomal dominant PKD usually occurs in adults ages 30 to 40 but can occur in children as well. Because it is an autosomal ..

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dominant disease, only one parent has to have the disease to pass it on to his or her child (but the parent will exhibit the disease as well, although some spontaneous mutation cases have been observed). This form accounts for 90 percent of PKD cases. Autosomal recessive PKD symptoms usually occur shortly after birth but sometimes as late as adolescence. For this type, both parents are carriers of the gene and do not show the disease.

3. PKD is diagnosed through imaging studies, such as ultrasound, CT scan, or MRI. Cysts have to be over 0.5 inch to be detected with imaging. With autosomal dominant PKD, the patient is symptomless for years while the cysts grow slowly. This is also true with autosomal recessive PKD; however, there is accompanying scarring of the liver as the disease progresses, and large cysts are not common.

4. High blood pressure, renal failure, preeclampsia during pregnancy, brain aneurysms, mitral valve prolapse, hernias, diverticulosis, and liver cysts, among others.

Investigate Online Take learning a step further by searching for relevant research articles on the Web. Visit science websites, such as those listed below, and begin by searching for key terms such as polycystic kidney disease, polycystic kidney disease treatment, polycystic kidney disease review, and autosomal polycystic kidney disease and see how what you’re learning in the course applies to science and medicine today. www.sciencedaily.com www.scientificamerican.com www.the-scientist.com www.ncbi.nlm.nih.gov/pubmed www.nature.com/subjects/polycystic-kidney-disease

Study Tips Direct students to the Study Tips feature located in the front of the book.

Mastering A&P Numerous items from Mastering A&P can be demonstrated in class, assigned as homework, or encouraged as study materials. These include practice tests and quizzes, animations and videos, Interactive Physiology (IP), Dynamic Study Modules, Audio Journeys, Practice Anatomy Lab (PAL), PhysioEx, flashcards, glossary, key terms, and more.

Interactive Physiology (IP) The following sections of Interactive Physiology are relevant to this chapter: Urinary System IP Anatomy Review Animation: Urinary IP2: Glomerular Filtration

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IP Animation: Glomerular Filtration IP Animation: Processing of Salt and Water in the Nephron IP Animation: Reabsorption and Secretion in the Proximal Tubule IP2: Tubular Reabsorption and Secretion Fluid, Electrolyte, and Acid-Base Balance IP Animation: Mechanisms to Control Acid-Base Homeostasis IP Animation: Acid-Base Problems IP Animation: Introduction to Body Fluids

PhysioEx10.0 The following sections of PhysioEx10.0 are relevant to this chapter:

Exercise 9: Renal System Physiology

Exercise 10: Acid-Base Balance

Animations and Videos The following animations and videos are relevant to this chapter:

Bone and Dissection Videos > Cow and Sheep Dissection > Sheep Kidney External; Sheep Kidney Internal, Part 1: General Overview; Sheep Kidney Internal, Part 2: Detailed Overview

Bone and Dissection Videos > Fetal Pig Dissection > Urogenital System

Practice Anatomy Lab (PAL)3.1: Including Mobile Flashcards The following sections of PAL3.1 are relevant to this chapter:

Human Cadaver > Urinary System

Anatomical Models > Urinary System

Histology > Urinary System ..

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Cat > Urinary System

Fetal Pig > Urinary System

Additional Study Tools The following video is relevant to this chapter:

Focus on Careers > Licensed Practical Nurse

Lecture Hints 1. To clear up a common misconception about the location of the kidneys, accurately describe their location in the superior lumbar region.

Key point: Kidneys are retroperitoneal, meaning behind the peritoneum and outside the peritoneal cavity. Students are usually surprised to learn that the kidneys are not in the same cavity as most of the other abdominal organs. Point out to students that the pain from kidney infections is often felt in the lower back. Injuries to the superior lumbar area (a blow to the lower back) also may involve injury to the kidney. The right and left kidneys are located at different heights; the left is higher because, on the right side, the liver occupies the space above the kidney.

2. Explain that the kidneys are held in place in the upper lumbar area by the fat surrounding them. Any condition leading to extreme weight loss can lead to nephroptosis, or drooping of the kidneys, which can then lead to kinked ureters and hydronephrosis.

Key point: Anorexia nervosa is one of the many conditions leading to nephroptosis. This mental illness, with its physical manifestation affecting the digestive and urinary systems, among others, is an interesting topic to use in explaining the process of nephroptosis and its sequelae.

3. Spend time explaining the gross anatomy of an individual kidney, then follow it with a presentation of the anatomy of a single nephron. Once both have been described, point out the regions in the kidney where the various structures of the nephron are located. For example, the loop of Henle drops into the renal medulla, whereas the glomerular capsule is in the cortex. Once students have this combined picture in mind, ask them to visualize a million or more nephrons in each kidney.

Key point: It is important for students to conceptualize the arrangement and sheer number of nephrons working in each kidney. This helps explain why a person can lose or donate one kidney, and still have a functioning urinary system that meets his or her needs. This is one of the many remarkable backup systems in the human body.

4. Compare the function of the two capillary beds found in the nephron.

Key point: The glomerulus pushes the fluid from blood out (filtration), and the peritubular capillaries reclaim the fluid by diffusion back into the blood (reabsorption).

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5. In the blood flow to and from the glomerulus, point out to the students that the arteries and veins have corresponding names (arcuate artery, arcuate vein), except that there is no segmental vein. Discuss the blood flow while pointing out the arteries and veins on a cross-sectional model of the kidney.

Key point: Students often get intimidated by learning about the blood supply to the kidney, but it helps if they realize that the nomenclature makes sense and is redundant between arteries and veins, with one small exception. For example, the renal artery supplies the kidney, branches off into the segmental artery that serves “segments” of the kidney, which in turn becomes the interlobular arteries that serve “lobes.” The dictionary definition of a lobe is a subdivision of a bodily organ or part bounded by fissures, which is indeed created by the renal columns running the borders of the renal pyramids.

6. Briefly go over differences in the structure of the cortical versus juxtamedullary nephrons, as well as how the peritubular capillary bed surrounding the juxtamedullary nephron is structured in such a way as to promote production of concentrated urine.

Key point: This drives home the idea of complementarity of structure and function. The specialized peritubular capillary called the vasa recta, along with the loop of Henle that dips deeply into the medulla of the kidney, can promote reabsorption of water to create concentrated urine as compared to the more convoluted peritubular capillaries surroundding the loop of Henle in the cortical nephron.

7. Remind students that the kidneys can function as endocrine organs, where peritubular capillary cells in the cortex produce erythropoietin.

Key point: This point reminds students that organs can function in more than one organ system; here the kidneys are an endocrine gland, and erythropoietin acts on the circulatory system to produce more red blood cells, which in turn affect the respiratory system by increasing oxygen levels.

8. Explain to students that the kidneys are not only the primary organs for elimination of wastes; they also control the plasma concentration of other important substances, such as water and electrolytes. This control is usually under the influence of hormones, including the two antidiuretics.

Key point: This is a good opportunity to show the interplay between the endocrine system and the urinary system.

9. First, itemize the normal constituents of urine, then make a second list of abnormal constituents and the possible causes for their presence in the urine. Emphasize that urine is not sterile.

Key point: Numerous medical conditions lead to abnormal constituents in the urine.

Give some examples, such as urinary tract infections, diabetes mellitus, and phenylketonuria, and explain the pathophysiology behind their presence. In 2014, more sophisticated lab tests showed that urine is never sterile; however, like gut bacteria, urine in the bladder contains flora that may maintain healthy homeostasis.

10. Discuss the numerous homeostatic imbalances a person on dialysis must face.

Key point: This is an opportunity to look at the big picture, rather than simply focusing on the primary function of an organ. Although students realize that kidneys are excretory organs, they forget about the other functions of the kidneys. Remind them that the kidneys regulate the rate of RBC production, are important in activation of vitamin D, ..

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and have a significant impact on blood pressure, pH, and, consequently, the cardiovascular system.

11. Discuss the reasons why urinary tract infections are more common in females than males, and differentiate between ascending urinary tract infections and descending urinary tract infections.

Key point: Females typically suffer from more urinary tract infections (UTIs) due to their shorter urethra, although males with prostatic hypertrophy also have a high incidence of UTI. Explain that ascending UTIs are much more common than descending UTIs because of the likelihood of pathogens entering through the urethral meatus.

12. Discuss what happens after pregnancy when incontinence issues may arise.

Key point: Incontinence after pregnancy may be caused by damage to nerves that control the bladder or because the positions of the urethra and bladder have changed during pregnancy. If the condition is more permanent, then surgery may be performed to lift the bladder neck upward and secure the bladder, or alternatively to secure the urethral sphincter in place. Also, pelvic floor muscle strengthening exercises, such as Kegel exercises, can be discussed.

13. Discuss some of the reasons for, and potential consequences of, intermittent and indwelling catheterization.

Key point: Catheterization is performed in order to obtain sterile urine specimens, to precisely monitor urine output, to remove urine from the bladder of an individual with a spinal cord injury, and for numerous other reasons. Urinary tract infection from contamination by pathogens is always a concern with catheterization.

14. Explain the connection between water and salt in maintaining blood volume and in blood pressure changes.

Key point: Wherever salt goes, water follows. Sodium ion is the electrolyte most responsible for the osmotic flow of water. A person who heavily salts food will end up retaining a good deal of water, potentially leading to edema, circulatory overload, and high blood pressure. Conversely, a person with low sodium intake may become dehydrated and experience low blood pressure.

15. Discuss the formation and removal of kidney stones. Explain why passage of kidney stones is extremely painful.

Key point: Renal calculi or kidney stones are crystals of uric acid salts and calcium that precipitate in the renal pelvis under conditions in which the urine becomes highly concentrated. Treatment methods include lithotripsy and ureteroscopy. Stones must be passed through the ureter, which is painful due to the sharpness of the calculi, as well as the back pressure (hydronephrosis) on the kidney tissue causing damage.

Classroom Demonstrations and Student Activities Classroom Demonstrations 1. Use a dissectible human torso model or a model of the urinary system to demonstrate the location of the organs of this system. Emphasize the differences between males and

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females and why it is easier for females to get UTIs. Also demonstrate how an enlarged prostate can impede urine flow in males.

2. Use a model of a longitudinally sectioned kidney to identify its major anatomical regions: cortex, medulla, pelvis, and associated blood supply. If the nephron is shown as a part of the model, also demonstrate the anatomic regions of the nephron and describe their specific functions in urine formation in detail.

3. Use a kidney model to trace renal blood flow. From entry into the kidney, to the nephron level, relate the glomerulus and peritubular capillaries to the overall pathway of blood in the kidney.

4. Bring in a synthetic urine sample and urinalysis test strips to discuss what is examined in a quick urine analysis in the physician’s office, as well as specific profiles associated with UTIs and diabetes.

5. Show a slide of transitional epithelium found in the bladder. Find areas of bladder distension and nondistension, and discuss complementarity of structure and function.

6. Invite speakers to talk to the class on treatment options, transplantation protocols, current research, and issues related to living with kidney failure. Discuss why kidney donation is becoming more commonplace, as well as the danger of continuing to play dangerous competitive sports with only one kidney.

Student Activities 1. Ask students to research the thirst mechanism and be prepared to discuss it in class.

Ingestion of carbonated soft drinks, coffee, and tea instead of water has caused the American public to be chronically dehydrated. Discuss the impact of this dehydration on overall health and how concentrated urine, indicated by its yellow color, signals the need for more water consumption, while clear and colorless urine indicates that water intake is sufficient.

2. Provide diagrams of the urinary system for students to label, or point to urinary system structures in a torso model and have students call out their respective functions.

3. Have students label a diagram of the nephron, with the processes that take place in each section, and what substances move in or out from the structures.

4. Reiterate the process of testing for edema in light of information now known about the urinary system. Have the students check themselves and note any evidence of edema.

5. Request that the students talk with a nurse at a local hospital to find out why fluid intake and output (I&O) records are so carefully maintained on ill patients. Use this information as the basis for class discussion.

6. Have students conduct a dialysis lab activity to help them understand the process of kidney dialysis. An example of a lab activity can be found here: teachers.yale.edu/curriculum/viewer/initiative_11.07.07_u 7. Discuss that the thirst mechanism is not well developed in humans, and humans often remain dehydrated for days after extreme fluid loss through sweat, even when liberal amounts of water are available. Following physical exertion in a hot and humid environment, most animals will drink precisely enough fluid to regain lost water weight.

Have students explain the connection of thirst with the hypothalamus. ..

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8. Discuss the premise of sports drinks such as Gatorade and the history behind the name Gatorade. Have students research and debate which types of sports drinks are most effective and why.

9. Have students research best practices to prevent UTIs, and why they are effective.

Media See page 164 for a listing of media resources.

1. Urinary System Introduction (Khan Academy, 2010, www.khanacademy.org/science/health-and-medicine/human-anatomy-andphysiology#introduction-to-the-kidneys). Videos, tutorials, and self-quiz on the urinary system.

2. Kidney Disease: Dialysis (NHS: 4 min., 2015, www.nhs.uk/conditions/Dialysis/Pages/Introduction.aspx). Short video about dialysis from the NHS of Great Britain.

3. The Urinary System, Parts 1 and 2 (Crash Course: 20 min., 2015, thecrashcourse.com/courses/anatomy). Discussion of the kidneys and urine in an entertaining, informative format.

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CHAPTER

16

The Reproductive System

Chapter Summary Of all the body systems, the most interesting to students is usually the reproductive system. Students frequently start with TEACHING TIP a good, although general, base of information and are eager to Students are initially intimibuild on what they already know, and many view this chapter dated about learning the as having “real world” relevance. For this reason, the material ovarian and uterine cycles found in this chapter often initiates good discussion in the and their control by the gonclassroom. adotropin and ovarian hormones. This concept may In this chapter, the male anatomy and reproductive be explained in a couple of functions are presented first. The testes and their accessory different approaches, and ducts are each described in order of sperm travel, followed by both approaches may need an explanation of the accessory glands and their secretions. to be incorporated to aid Semen is the combination of the sperm with the accessory students in their understandgland secretions. The secretions from the seminal vesicles and ing. (1) Step-by step: The starting point is how the prostate gland combine with sperm as the sperm travels anterior pituitary, through through each structure, and the secretions from the gonadotropins, triggers bulbourethral glands cleanse the urethra of acid and serve as a ovarian hormones that initilubricant during sexual intercourse. The role of the scrotum in ate changes in the ovaries temperature regulation is explained, as is the function of the and uterus. Segment the presentation of Figure penis in sperm delivery. Following the anatomy of the male 16.12. Circle or show only reproductive system is an overview of the process of the time point discussed in spermatogenesis, or sperm production. Testosterone each step. (2) Discuss the production is explained, and the secondary sex characteristics hormone cycles together that this hormone stimulates are outlined. first, then discuss the ovariThe next section of this chapter covers the female anatomy an and uterine cycles together. Unite the two and reproductive functions. The ovaries and their accessory concepts together by going ducts are each described, followed by an explanation of the over Figure 16.12. With roles of the uterus and vagina, as well as a description of the either approach, discuss the external female genitalia and female perineum. Oogenesis, or cyclic nature of all of the egg production, and the ovarian cycles are presented next. events. Also draw the students’ attention to how esThe roles of hormones in regulating the cyclic changes that trogen levels play both a occur monthly in the ovary are explained, followed by a negative and positive feeddiscussion of the uterine cycle. The biological role of the back role in gonadotropin mammary glands to produce milk completes this overview of secretion. female reproduction.

The final section of this chapter provides a survey of pregnancy and embryonic development. The obvious joint role of the male and female reproductive systems is to produce offspring. The process of meiosis for gamete production to mitosis once fertilization occurs is an important underlying concept. Beginning with fertilization, the process proceeds through embryonic and fetal ..

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development, culminating in childbirth. The anatomical and physiological changes that occur to the mother during pregnancy are discussed, and the process of childbirth and the three stages of labor are presented. In the section on developmental aspects, some of the more intriguing homeostatic imbalances are discussed, including pseudohermaphroditism and the chromosomal abnormalities of XO females and YO males; the section also includes a brief overview of puberty as the initiation of reproductive functioning, as well as menarche, the end of reproductive capability in women.

Suggested Lecture Outline I. 16.1 Anatomy of the Male Reproductive System (pp. 541–545) A. 16.1a Testes (p. 541) B. 16.1b Duct System (pp. 541–543) 1. Epididymis 2. Ductus Deferens 3. Urethra C. 16.1c Accessory Glands and Semen (pp. 543–544) 1. Seminal Vesicles 2. Prostate 3. Bulbourethral Glands 4. Semen D. 16.1d External Genitalia (pp. 544–545)

II. 16.2 Male Reproductive Functions (pp. 545–549) A. 16.2a Spermatogenesis (pp. 545–547) B. 16.2b Testosterone Production (pp. 547, 549)

III. 16.3 Anatomy of the Female Reproductive System (pp. 549–553) A. 16.3a Ovaries (p. 549) MEDIA TIP

B. 16.3b Duct System (pp. 549–552) 1. Uterine Tubes 2. Uterus 3. Vagina

Science and Sex Bias (PBS: 4 min., 2016, www.pbs.org/wgbh/nova/bo dy/sex-bias-mantis.html). A short video clip discussing previous bias of research on males versus females in various species. This is a good springboard for discussion about the importance of medical research and treatments to be conducted in both men and women.

C. 16.3c External Genitalia and Female Perineum (pp. 552– 553)

IV. 16.4 Female Reproductive Functions and Cycles (pp. 553–556) A. 16.4a Oogenesis and the Ovarian Cycle (pp. 553–555) B. 16.4b Hormone Production by the Ovaries (pp. 555– 556) C. 16.4c Uterine (Menstrual) Cycle (pp. 556–557) 1. Days 0–4: Menstrual Phase 2. Days 5–14: Proliferative Phase 3. Days 15–28: Secretory Phase 175 INSTRUCTOR GUIDE FOR ESSENTIALS OF HUMAN ANATOMY & PHYSIOLOGY, 13e

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V. 16.5 Mammary Glands (pp. 556, 558–559) VI. 16.6 Pregnancy and Embryonic Development (pp. 559–569) A. 16.6a Accomplishing Fertilization (pp. 560–561) B. 16.6b Events of Embryonic and Fetal Development (pp. 561–565) C. 16.6c Effects of Pregnancy on the Mother (pp. 565–567) 1. Anatomical Changes 2. Physiological Changes a. Gastrointestinal System b. Urinary System c. Respiratory System d. Cardiovascular System D. 16.6d Childbirth (pp. 567–569) 1. Initiation of Labor 2. Stages of Labor a. Stage 1: Dilation Stage b. Stage 2: Expulsion Stage c. Stage 3: Placental Stage

VII. 16.7 Developmental Aspects of the Reproductive System (pp. 569, 571, 573) Note: For a list of Key Terms for this chapter, please go to Mastering A&P > Study Area > Additional Study Tools > Key Terms > Chapter 16.

Learning Objectives 16-1 Discuss the common purpose of the reproductive system organs.

16-2 When provided with a model or diagram, identify the organs of the male reproductive system, and discuss the general function of each.

16-3 Name the endocrine and exocrine products of the testes.

16-4 Discuss the composition of semen, and name the glands that produce it.

16-5 Trace the pathway followed by a sperm from the testis to the body exterior.

16-6 Define circumcision, erection, and ejaculation.

16-7 Define spermatogenesis and meiosis.

16-8 Describe the structure of a sperm, and relate its structure to its function.

16-9 Describe the effect of FSH and LH on testis functioning.

16-10 Identify the organs of the female reproductive system, and discuss the general function of each.

16-11 Describe the functions of the vesicular follicle and corpus luteum of the ovary.

16-12 Define endometrium, myometrium, and ovulation.

16-13 Indicate the location of the following regions of the female uterus: cervix, fundus, body.

16-14 Define oogenesis.

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16-16 Describe the phases and controls of the menstrual cycle.

16-17 Describe the structure and function of the mammary glands.

16-18 Define fertilization and zygote.

16-19 Describe implantation.

16-20 Distinguish between an embryo and a fetus.

16-21 List the major functions of the placenta.

16-22 Indicate several ways that pregnancy alters or modifies the functioning of the mother’s body.

16-23 List several agents that can interfere with normal fetal development.

16-24 Describe how labor is initiated, and briefly discuss the three stages of labor.

16-25 Describe the importance of the presence/absence of testosterone during embryonic development of the reproductive system organs.

16-26 Define menarche and menopause.

16-27 List common reproductive system problems seen in adult and aging men and women.

Resources for Teaching Online Discussion Board Topic: Homeostatic Imbalance—Cervical Cancer In the textbook on page 552, the Homeostatic Imbalance section discusses cervical cancer, which is commonly diagnosed in women ages 30–50. The Pap smear is the most important diagnostic tool for this disease. Engage your students by using the following discussion questions in lecture or by posting them to the discussion board on your course management system.

Discussion Questions 1. What is thought to cause cervical cancer?

2. How is cervical cancer diagnosed?

3. What vaccine is now given to prevent cervical cancer, what strains of human papilloma virus (HPV) do they target, and why is there controversy surrounding the vaccine administration?

4. What are some current treatment strategies?

Potential Student Responses: 1. Cervical cancer is caused by the human papilloma virus (HPV). This virus is passed between individuals through sexual contact. In addition, other risk factors raise the chance that the viral infection will result in cancer; they include smoking, being overweight, a diet low in fruits and vegetables, genetic susceptibility, having other STDs such as chlamydia and HIV, having sex at a young age, having many sex partners, having three or more pregnancies, and long-term birth control pill use, among others.

2. Cervical cancer is a slow-growing cancer, and therefore early stages of this disease are asymptomatic. There are two commonly conducted tests: the Pap smear and the HPV DNA test. The Pap smear looks for cells that look abnormal and may be precancerous,

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and the test should be done within three years of first sexual activity but no later than 21 years of age. The Pap smear should be done every year until 30 years of age with three continuous years of regular results, after which the test can be done every two or three years; if you have certain risk factors, your doctor may recommend more-frequent Pap smears, regardless of your age. The HPV DNA test looks at whether cervical cells contain the DNA of HPV strains that cause cervical cancer. This test is usually done in women over 30 in conjunction with a Pap smear, or those women with slightly abnormal Pap smear results. If an abnormal Pap smear is found, a colposcopy, endocervical curettage, and/or biopsy may also be conducted to help diagnose cervical cancer.

3. The HPV vaccine is now administered to prevent cervical cancer. It is a series of three dose administrations; the second dose is given 1 to 2 months after the first dose, and the third dose is administered 6 months after the first dose. The vaccine is typically administered to girls ages 11 to 12. The goal is to vaccinate and boost immunity in girls before they are sexually active, although it is still recommended for young women who are sexually active. However, the caveat is that sexually active women may already be exposed to the virus, in which case the vaccine will not help. The vaccine appears to be safe, although, like other vaccines, there is a chance of severe reactions; also, because it is still in its early stages, any side effects that may occur years later are not yet known.

The cervical cancer vaccine is now part of a routine vaccination schedule, but its requirement for school admission is still decided on a state-by-state basis. It is also recommended that boys receive this vaccine at ages 11 to 12, in a three-dose series, to prevent some types of genital warts. The vaccine does not comprehensively protect against cervical cancer, as there are many strains of the HPV virus, but current/commonly found vaccines are either bivalent (Cervarix) or quadrivalent (Gardasil)—that is they target either two or four main strains, respectively, that are responsible for cervical cancer. For the latter vaccine, two target strains are those that are responsible for genital warts and abnormal Pap smears, rather than cervical cancer.

Starting in October 2016, a nine-valent vaccine (Gardasil-9) that protects against nine strains of HPV is recommended, with a two-dose regimen for 9- to 14-year-olds and a three-dose regimen for 16- to 26-year-olds.

4. Surgical removal of cancerous tissue, chemotherapy, and/or radiation therapy.

Investigate Online Take learning a step further by searching for relevant research articles on the web. Visit science websites, such as those listed below, and begin by searching for key terms such as cervical cancer, human papilloma virus, cervical cancer vaccine, cervical cancer treatment, cervical cancer screening, and HPV cervical cancer and see how what you’re learning in the course applies to science and medicine today. www.sciencedaily.com www.scientificamerican.com www.the-scientist.com www.ncbi.nlm.nih.gov/pubmed

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Study Tips Direct students to the Study Tips feature located in the front of the book.

Mastering A&P Numerous items from Mastering A&P can be demonstrated in class, assigned as homework, or encouraged as study materials. These include practice tests and quizzes, animations and videos, Interactive Physiology (IP), Dynamic Study Modules, Audio Journeys, Practice Anatomy Lab (PAL), PhysioEx, flashcards, glossary, key terms, and more.

Animations and Videos The following animations and videos are relevant to this chapter:

BioFlix > Meiosis

Bone and Dissection Videos > Cat Dissection > Male Reproductive Structures; Female Reproductive Structures

Bone and Dissection Videos > Fetal Pig Dissection > Urogenital System

Practice Anatomy Lab (PAL)3.1: Including Mobile Flashcards The following sections of PAL3.1 are relevant to this chapter:

Human Cadaver > Reproductive System

Anatomical Models > Reproductive System

Histology > Reproductive System

Cat > Reproductive System

Fetal Pig > Reproductive System

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Lecture Hints 1. Remind students that the male reproductive system shares structures with the urinary system, whereas the female reproductive system does not. Point out that this difference is evident even during embryonic development.

Key point: Organs can participate in more than one organ system; examples include the pancreas (endocrine and digestive systems) and the hypothalamus (nervous and endocrine systems).

2. Point out that development of the testes within the abdominal cavity is similar to development of the ovaries but that the testes descend into the scrotum for temperature control of sperm, usually prior to birth. Cryptorchidism, or undescended testes, is a condition that can lead to sterility unless surgically corrected. Hot tubs and tight jeans can impact sperm viability.

Key point: This reinforces the concept of complementarity of structure and function.

3. Discuss the conditions of hypospadias and epispadias and their consequences.

Key point: Hypospadias is the opening of the urethra on the undersurface of the penis, whereas epispadias is the opening of the urethra on the dorsal surface. Depending on severity, both conditions can decrease male fertility by causing inadequate deposition of sperm, and both are usually corrected surgically.

4. Discuss the components of semen, what they do, and from which glands they are secreted.

Key point: Some students mistakenly think semen and sperm are synonymous and are surprised to learn that semen is a combination of several secretions. This is an excellent opportunity to also reinforce physiology of the accessory glands (seminal vesicles, prostate, and bulbourethral glands) and the specific functions of the secretions released from each gland (providing energy for sperm, ensuring alkalinity of semen to neutralize acidic vaginal environment, fight off bacteria, dilute sperm, and enhance sperm motility).

5. Discuss prostatic cancer and benign prostatic hypertrophy (BPH), and differentiate between their signs, symptoms, and treatment options. Discuss the current guidelines for PSA levels for prostate cancer screening.

Key point: BPH is common in men over 50 and results in urinary urgency, frequency in urination, bladder infection, and other urinary difficulties. The hypertrophied prostatic tissue that is strangling the urethra is often removed surgically, or newer treatments, including drugs and radiation, can be used to shrink the enlarged tissue. Prostatic cancer is the second leading cause of cancer death in males in the United States. A screening technique that tests prostate-specific antigen (PSA) has risks associated with it, and diagnosis of prostate cancer may not change the life expectancy of the patient. The American Urological Association guidelines for 2013 advise that men ages 40 to 54 be screened and that anyone outside that age group make a shared decision with their physician about whether to undergo testing.

6. Distinguish between spermiogenesis and spermatogenesis.

Key point: The terms are very similar, so it is important to emphasize the difference to the students: spermiogenesis is the last stage of sperm development when all excess cytoplasm is sloughed off and the mature sperm is visualized, while spermatogenesis is ..

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sperm production as a whole. Spermiogenesis is, therefore, the last phase of spermatogenesis.

7. Outline spermatogenesis and oogenesis together to help students understand their similarities as well as differences.

Key point: This is a good opportunity to emphasize the differences between mitosis and meiosis. Mitosis was covered in Chapter 3 (Cells and Tissues). In addition, note how four sperm can be created through meiosis in the male, whereas only one functional ovum results from meiosis in the female.

8. Itemize the secondary sex characteristics of both males and females. Remind students of the role of hormones in sexual development, and discuss the effects of homeostatic imbalances of these hormones.

Key point: This becomes a good point of discussion because there is increasing scientific concern over the exposure of both males and females to synthetic estrogens from plastics, pesticides, and growth hormones in food.

9. Note that the layers of the uterus follow a pattern of layering we have seen with other organs and tissues. Also, point out that the cervix refers to the cylinder-shaped neck of tissue located at the lowest part of the uterus. It can be related to the cervical vertebrae found in the actual neck region because of its shape.

Key point: The endometrium, myometrium, and perimetrium follow a pattern seen with such organs as the heart and nerves. Recognizing this pattern helps students better visualize the layers. Recognizing root word meanings, such as “cervix” (or “neck”), helps explain why it can be used in reference to entirely different regions.

10. Discuss the incidence of cervical, uterine, ovarian, and breast cancer in women, as well as screening tools and treatment options.

Key point: An annual Pap smear is the screening tool of choice for early detection of cervical cancer. Breast cancer is the leading cause of death in American women, and screening includes monthly self-examination and annual mammography for certain age groups. Early detection of uterine or ovarian cancer is still unsatisfactory.

11. Outline the process of fertilization and follow the path of the fertilized egg from conception to implantation. Discuss ectopic pregnancy and placenta previa.

Key point: Students are usually quite interested in the fertilization process and have often heard of complications that can arise. Explaining that fertilization generally takes place in the fallopian tubes helps explain the incidence of ectopic pregnancy, and implantation close to the cervical opening explains the seriousness of placenta previa.

12. Discuss the functions of FSH and LH in both males and females.

Key point: These gonadotropic hormones are found in both sexes with analogous roles: in males, FSH stimulates spermatogenesis, while LH stimulates testosterone production; in females, FSH stimulates oogenesis as part of follicle maturation, whereas LH stimulates ovulation and, consequently, progesterone and estrogen production.

13. Discuss the time points for the zygote, embryo, fetus, and neonate.

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formation; fetus is the developing organism from the ninth week until delivery; neonate is the “newborn” baby.

14. Clearly differentiate between the terms prostate and prostrate and between perineum and peritoneum.

Key point: These terms are often used incorrectly by students and laypersons.

15. Explain some of the genetic conditions associated with chromosomal abnormalities, such as Turner syndrome and Down syndrome. Remind the students of previous discussions about X-linked disorders such as hemophilia and choroideremia.

Key point: This is an excellent opportunity to give a brief overview of some of the more prominent or intriguing hereditary conditions.

16. Describe eclampsia, or toxemia of pregnancy, and discuss early detection and treatment.

Key point: Eclampsia, the most serious complication of pregnancy, is a severe hypertensive disorder characterized by convulsions and coma, which can lead to death.

Early detection is critical, and the primary means of early detection is through urine testing for proteinuria, an excellent early sign of increasing blood pressure. Treatment involves bed rest and seizure management.

17. Discuss the different types of birth control methods, including the “morning-after pill.”

Explain the efficacy and side effects of each.

Key point: Students may be aware of only one or two methods and may not understand how they actually prevent contraception.

18. Discuss what situations necessitate C-sections.

Key point: Although a common procedure, students may not be aware of the conditions that lead to a C-section, such as stalled labor, abnormal position of the baby, multiple babies, problems with the placenta or umbilical cord, reduced oxygen supply to the baby (dystocia), previous C-sections, health problems with mother and/or child, or baby too large for vaginal delivery, among other issues.

19. Discuss the impact of ethanol ingestion and cigarette smoking during pregnancy.

Key point: Ethanol ingestion is most harmful in the first three months of pregnancy (discuss fetal alcohol syndrome). It has been observed that babies born to mothers who smoke experience higher incidences of cleft lip/palate, sudden infant death syndrome (SIDS), low birth weight/premature birth, and placental disruption.

Classroom Demonstrations and Student Activities Classroom Demonstrations 1. Use a dissectible human torso model to demonstrate the location of the reproductive organs in the male and female. Trace the pathway that semen travels through the ducts in males and when seminal fluid components are added en route, and for females trace the travels of the oocyte after ovulation and fertilization.

2. Use a “pregnant” torso model to illustrate the most desirable positioning of the placenta and the vertex presentation of a fetus, along with the placement of fetuses during a multiple pregnancy. Also, demonstrate a breech delivery placement and other nonvertex placements.

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3. Display various types of temporary contraception as an adjunct to a discussion of birth control. Discuss how each of the contraception methods works as either a physical barrier (condoms, IUDs, diaphragms, cervical caps) or by impacting the female hormonal cycle and, therefore, ovarian and uterine cycles (birth control pills, patches, and implants).

4. Use a torso model to discuss the vasectomy procedure in the male and the tubal ligation procedure in the female.

5. Use models and/or animations showing the process of meiosis in spermatogenesis and oogenesis. Emphasize the concept that the haploid cells unite to form diploid cells, which then undergo mitosis. Also, discuss the implications of heredity with meiosis.

6. Discuss the process of gender reassignment surgery using diagrams and the hormonal and psychological preparation for this procedure.

7. Show pictures, models, or preserved specimens of human embryos or fetuses in various stages of development to illustrate the later changes that occur during gestation.

8. Show pictures of common STD pathophysiology, and discuss symptoms, prevention, and treatment options.

9. Invite an obstetrician, obstetrics nurse, midwife, and doula to talk about childbirth from each of their perspectives.

10. Form a panel of women who have gone through pregnancy and childbirth, and ask them to discuss their experiences with the class. Include discussion of breast-feeding of the neonate as well.

11. Invite a maternal-fetal medicine obstetrician to discuss various situations of high-risk pregnancies.

12. Invite a lactation consultant to discuss her experiences and advice for breastfeeding.

Student Activities 1. Have students bring in articles that deal with the effects of maternal drug use or alcoholism on the fetus. Use this information as a starting point for class discussion, including a discussion of fetal alcohol syndrome.

2. Ask students to research sexually transmitted diseases and present their findings on the top five sexually transmitted diseases (STDs) in their local area compared to the national figures.

3. Have students use masking tape/sticky pad labels to identify structures on male and female reproductive tract models.

4. Have students do a picture sort (put pictures in the correct progression of the process) of mitosis, meiosis, oogenesis, and spermatogenesis to aid in their understanding of these concepts.

5. Have students create and play a Jeopardy-style game, with questions based on the uterine cycle, ovarian cycle, and female hormone cycle.

6. Have students research and report on advances in assisted fertilization as a starting point for class discussion. Discuss what body conditions impact fertility in both men and women.

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7. Have students read the Pulitzer Prize–winning novel Middlesex by Jeffrey Eugenides as a potential extra-credit project (this is extensive reading). Ask them to discuss the topic of being intersex and how it relates to concepts discussed in this chapter.

Media See page 164 for a listing of media resources.

1. Reproductive System (Khan Academy: 2014, www.khanacademy.org/science/healthand-medicine/human-anatomy-and-physiology/reproductive-systemintroduction/v/welcome-to-the-reproductive-system). Videos, tutorials, and practice questions about the reproductive system.

2. Three Facts About Periods (PBS: 6 min., 2016, www.pbs.org/wgbh/nova/body/threefacts-periods.html).

3. Gender Biology: Men and Women Really Are Different (FHS: 22 min., 2001, VHS, DVD, 3-year streaming webcast). This program explores the emerging field of genderbased biology and gender implications in medical treatments.

4. Reproductive System Parts 1–4 (Crash Course, 43 min., 2015, thecrashcourse.com/courses/anatomy). Female and male reproductive systems, sex and fertilization, pregnancy, and development are discussed.

5. The Anatomy of Reproduction (Institute for Plastination; 50 min, 2005, DVD). Male and female reproductive system anatomy and function are summarized with the use of cadavers.

6. NOVA: Life's Greatest Miracle (PBS: 60 min, 2001, www.pbs.org/wgbh/nova/body/lifegreatest-miracle.html). This video documents human development from conception to birth through microscopy and medical imaging.

7. Growing Up Trans (PBS: 85 min., 2015, www.pbs.org/wgbh/frontline/film/growing-uptrans). Interviews with transgender children and adolescents and the use of hormone blockers.

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