Chapter 1. The foundational Concepts of Clinical Practice
MULTIPLE CHOICE
1. The type of control system that can sometimes cause instability and vicious cycles is called
A) negative feedback.
B) feed-forward control.
C) positive feedback.
D) adaptive feedback.
E) delayed negative feedback.
ANS: C
Feedback:
Positive feedbackamplifiesa change inthesystem,oftenleadingtoinstabilityorviciouscycles. For example, in certain pathological conditions, positive feedback can exacerbate the problem rather than stabilizing it, unlike negative feedback systems, which promote homeostasis.
2. Which of the following is an example of positive feedback in the body?
A) Return of blood pressure toward normal after a hemorrhage
B) Generation of action potentials in nerves
C) Increased respiration rate caused by accumulation of carbon dioxide in the blood
D) Decreased sympathetic nervous system activity that occurs in response to increased blood pressure
ANS: B
Feedback:
Positive feedback in nerve action potentials occurs when the depolarization of the membrane causes sodium channels to open, leading to further depolarization. Other options, such as the return of blood pressure to normal after hemorrhage, are examples of negative feedback.
3. The vascular, hemodynamic stage of acute inflammationis initiatedby momentary vasoconstriction followed by vasodilation that causes localized:
A) bleeding.
B) congestion.
C) pale skin.
D) coolness.
ANS: B
Feedback:
Vasodilation increases blood flow to the injured area, causing localized congestion, which is the accumulation of blood in the vessels. This leads to redness and warmth. Bleeding and coolness are not typical of the hemodynamic stage, and pale skin would result from vasoconstriction, not vasodilation.
4. The cellular stage of acute inflammation is marked by the movement of leukocytes into the area. Which of the following cells arrives early in great numbers?
A) Basophils
B) Lymphocytes
C) Neutrophils
D) Platelets
ANS: C
Feedback:
Neutrophils are the first leukocytes to arrive at the site of acute inflammation in large numbers. They play a key role in phagocytosing pathogens and cellular debris. Basophils and lymphocytes are not the primary responders in acute inflammation, and platelets are involved in clotting rather than leukocyte infiltration.
5. Which of the following is an example of a “feed-forward” control system?
A) The arterial baroreceptor system
B) The progressive nature of uterine contractions during childbirth
C) Control of skeletal muscle movements by the brain
D) Generation of an action potential
ANS: C
Feedback:
Feed-forward control systems anticipate a change and initiate a response before it occurs. The brain controlling skeletal muscle movement is an example, as it predicts the required actions and adjusts muscle control accordingly. Other examples, such as uterine contractions during childbirth, are positive feedback systems.
6. The phagocytosis process involves three distinct steps. What is the initial step in the process?
A) Engulfment
B) Intracellular killing
C) Antigen margination
D) Recognition and adherence
ANS: D
Feedback:
Phagocytosis begins with the recognition and adherence of pathogens or debris by phagocytic cells, such as neutrophils or macrophages. This is followed by engulfment and intracellular killing. Antigen margination is not a recognized step in phagocytosis.
7. Which of the following mediators of inflammation causes increased capillary permeability and pain?
A) Serotonin
B) Histamine
C) Bradykinin
D) Nitric oxide
ANS: C
Feedback:
Bradykinin is a potent inflammatory mediator that increases capillary permeability and induces pain. While histamine and serotonin also increase permeability, they do not directly cause pain. Nitric oxide is involved in vasodilation but not in pain mediation.
8. Inflammatory exudates are a combination of several types. Which of the following exudates is composed of enmeshed necrotic cells?
A) Serous
B) Fibrinous
C) Suppurative
D) Membranous
ANS: D
Feedback:
Membranous exudates are characterized by necrotic cells enmeshed in a fibrinous matrix, often forming on mucosal surfaces. Suppurative exudates (pus) are rich in neutrophils, while serous and fibrinous exudates are associated with clear fluid and fibrin, respectively.
9. The acute-phase systemic response usually begins within hours of the onset of inflammation and includes:
A) fever and lethargy.
B) decreased C-reactive protein.
C) positive nitrogen balance.
D) low erythrocyte sedimentation rate.
ANS: A
Feedback:
The acute-phase response is mediated by cytokines such as IL-1, IL-6, and TNF-α, which act on the hypothalamus to induce fever and on other systems to cause lethargy. This response also involves an increase in C-reactive protein and erythrocyte sedimentation rate, not a decrease.
10. The characteristic, localized cardinal signs of acute inflammation include:
A) fever.
B) fatigue.
C) redness.
D) granuloma.
ANS: C
Feedback:
The cardinal signs of acute inflammation are localized redness (rubor), swelling (tumor), heat (calor), pain (dolor), and loss of function. Redness occurs due to vasodilation and increased blood flow to the injured area, which is a hallmark of the inflammatory response. Fever and fatigue, while associated with inflammation, are systemic rather than localized signs, and granuloma formation is characteristic of chronic inflammation.
11. In contrast toacute inflammation, chronic inflammation ischaracterized by which of the following phenomena?
A) Profuse fibrinous exudation
B) A shift to the left of granulocytes
C) Metabolic and respiratory alkalosis
D) Lymphocytosis and activated macrophages
ANS: D
Feedback:
Chronic inflammation involves the recruitment of lymphocytes and macrophages, which become activated and contribute to tissue remodeling and fibrosis. Acute inflammation is characterized by neutrophils and exudation, whereas fibrinous exudation, granulocyte shifts, and alkalosis are not hallmarks of chronic inflammation.
12. Exogenous pyrogens (interleukin-1) and the presence of bacteria in the blood lead to the release of endogenous pyrogens that:
A) stabilize thermal control in the brain.
B) produce leukocytosis and anorexia.
C) block viral replication in cells.
D) inhibit prostaglandin release.
ANS: B
Feedback:
Endogenous pyrogens like IL-1 and TNF-α induce systemic responses such as fever, leukocytosis,and anorexia.They act onthehypothalamustomodulate temperature and onother tissues to mediate inflammation. They do not stabilize thermal control, block viral replication, or inhibit prostaglandin release.
13. An older adult patient has just sheared the skin on her elbow while attempted to boost herself up in bed, an event that has precipitated acute inflammation in the region surrounding the wound. Whichofthefollowingeventswill occurduringthevascularstage ofthepatientsinflammation?
A) Outpouring of exudate into interstitial spaces
B) Chemotaxis
C) Accumulation of leukocytes along the epithelium
D) Phagocytosis of cellular debris
ANS: A
Feedback:
During the vascular stage of inflammation, increased vascular permeability leads to the outpouring of protein-rich exudate into interstitial spaces, contributing to swelling. Chemotaxis and leukocyte accumulation occur in the cellular stage, and phagocytosis is a subsequent step.
14. Which of the following individuals most likely has the highest risk of experiencing chronic inflammation?
A) A patient who has recently been diagnosed with type 2 diabetes
B) A patient who is a carrier of an antibiotic-resistant organism
C) A patient who is taking oral antibiotics for an upper respiratory infection
D) A patient who is morbidly obese and who has a sedentary lifestyle
ANS: D
Feedback:
Chronic inflammation is strongly associated with obesity and a sedentary lifestyle due to the persistent release of pro-inflammatory cytokines from adipose tissue. In contrast, type 2 diabetes, antibiotic resistance, or short-term antibiotic use may be linked to inflammation but are not as directly associated with chronic inflammatory processes.
15. Which of the following core body temperatures is within normal range?
A) 35.9C (96.6F)
B) 38.0C (100.4F)
C) 35.5C (95.9F)
D) 37.3C (99.1F)
ANS: D
Feedback:
The normal range for core body temperature is typically 36.1°C to 37.5°C (97°F to 99.5°F). A temperature of 37.3°Cfalls withinthisrange, while the other options either fall below or exceed it, indicating hypothermia or fever.
16. A postsurgical patient who is recovering in the postanesthetic recovery unit states that she is freezing cold. Which of the following measures is likely to be initiated in the patients hypothalamus in an effort to reduce heat loss?
A) Opening of arteriovenous (AV) shunts
B) Reduced exhalation of warmed air
C) Contraction of pilomotor muscles
D) Decreased urine production
ANS: C
Feedback:
Contraction of pilomotor muscles causes "goosebumps," which helps trap a layer of air close to the skin, reducing heat loss. Opening AV shunts increases heat loss, and reduced exhalation or decreased urine production are not thermoregulatory responses to cold.
17. When a person is at rest, how much time is required for the blood in the circulation to traverse the entire circulatory circuit?
A) 1 second
B) 1 minute
C) 3 minutes
D) 4 minutes
E) 5 minutes
ANS: B
Feedback:
At rest, the human circulatory system is designed to complete a full cycle of blood circulation in approximately one minute. This reflects the cardiac output and the speed at which the heart pumps blood through systemic and pulmonary circuits.
18. An elderly patient is dressed only in a hospital gown and complains of a draft in her room. Consequently, she has requested a warm blanket while she sits in her wheelchair. Which of the following mechanisms of heat loss is most likely the primary cause of her request?
A) Evaporation and conduction
B) Radiation and convection
C) Conduction and convection
D) Convection and evaporation
ANS: B
Feedback:
Heat is lost through radiation to cooler objects in the environment and convection when air currents remove heat from the body surface. Conduction and evaporation are less relevant in this scenario.
19. Which of the following pathophysiologic processes are capable of inducing the production of pyrogens? Select all that apply.
A) Acute inflammation
B) Obesity
C) Myocardial infarction
D) Malignancy
E) Renal failure
ANS: A, C, D
Feedback:
Acute inflammation, myocardial infarction, and malignancy trigger the release of endogenous pyrogens, such as IL-1 and TNF-α, which stimulate fever. Obesity and renal failure may contribute to inflammation but are not primary inducers of pyrogen production.
20. Which of the following patients is most likely to be susceptible to developing a neurogenic fever?
A) A patient who has stage II Alzheimer disease
B) A patient who has sustained a head injury in a bicycle crash
C) A patient who has become delirious after the administration of a benzodiazepine
D) A patient who has begun taking a selective serotonin-reuptake inhibitor (SSRI) for the treatment of depression
ANS: B
Feedback:
Neurogenic fever results from damage to the hypothalamus, often due to head trauma or injury. Alzheimer’s disease, delirium from benzodiazepines, or SSRIs are less likely to disrupt hypothalamic thermoregulation directly.
21. Patients are commonly administered antipyretics when their oral temperature exceeds 37.5C (99.5F). Which of the following statements related to the rationale for this action is most accurate?
A) Temperatures in excess of 37.5C (99.5F) can result in seizure activity.
B) Lower temperatures inhibit the protein synthesis of bacteria.
C) There is little empirical evidence for this treatment modality.
D) Most common antipyretics have been shown to have little effect on core temperature.
ANS: C
Feedback:
While antipyretics are commonly used, there is limited evidence to support their efficacy in treating fever or improving outcomes. Other statements are incorrect, as moderate fever does not typically cause seizures, and antipyretics do effectively lower core temperature.
22. A patient has sought care because of recent malaise and high fever. Upon assessment, the patient states that his current fever began two days earlier, although he states that for the last 2 weeks he is in a cycle of high fever for a couple of days followed by a day or two of normal temperature. Which of the following fever patterns is this patient experiencing?
A) Recurrent fever
B) Remittent fever
C) Sustained fever
D) Intermittent fever
D
Feedback:
Recurrent (or relapsing) fever is characterized by alternating periods of fever and normal temperature over several days. This distinguishes it from remittent fever, sustained fever, or intermittent fever (which fluctuates within 24 hours).
23. A febrile, 3-week-old infant has been brought to the emergency department by his parents and is currently undergoing a diagnostic workup to determine the cause of his fever. Which of the following statements best conveys the rationale for this careful examination?
A) The immature hypothalamus is unable to perform normal thermoregulation.
B) Infants are susceptible to serious infections because of their decreased immune function.
C) Commonly used antipyretics often have no effect on the core temperature of infants.
D) Fever in neonates is often evidence of a congenital disorder rather than an infection.
ANS: B
Feedback:
Neonates have immature immune systems, making them highly susceptible to infections that can cause fever. The hypothalamus can regulate temperature normally, and fever in neonates is more often infectious than congenital.
24. An 84-year-old patients blood cultures have come back positive, despite the fact that his oral temperature has remained within normal range. Which of the following phenomena underlies the alterations in fever response that occur in the elderly?
A) Disturbance in the functioning of the thermoregulatory center
B) Increased heat loss by evaporation
C) The presence of comorbidities that are associated with lowered core temperature
D) Persistent closure of arteriovenous shunts
ANS: A
Feedback:
Aging impairs the hypothalamus’s ability to regulate temperature, resulting in a blunted fever response even during severe infections. Increased heat loss, comorbidities, or AV shunt closure are less likely explanations.
25. Which of the following is an example of negative feedback?
Example 1: Arterial baroreceptor control of blood pressure
Example 2:Excitationofthe respiratorycenter byincreasedbloodcarbondioxide concentration
Example 3: Hemorrhagic shock caused by severe blood loss
A) Example 1 only
B) Example 2 only
C) Example 3 only
D) Examples 1 and 2, but not 3
E) Examples 1, 2, and 3
Feedback:
Examples 1 and 2 are classic negative feedback mechanisms, where changes in blood pressure or carbon dioxide levels are detected and corrected to maintain homeostasis. Hemorrhagic shock, however, is a pathological condition where the body fails to stabilize itself, often leading to positive feedback loops and further deterioration.