HUMAN BODY. INTERACTION.

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SCIENCE 5.

UNIT 2. HUMAN BODY. INTERACTION.

C.E.I.P. SANTA ANA (Madridejos)

CONTENTS: 1.- Vital functions in human: nutrition / interaction / reproduction.

2.- Interaction function: 3.- Sense organs: sight / hearing / smell / taste / touch 4.- Nervous system: central / peripheral nervous system.

5.- Locomotor system: skeleton / muscles.

1.– VITAL FUNCTIONS IN HUMAN. Vital functions in humans are the same as the rest of living beings: nutrition, interaction and reproduction. Human being is a multicellular organism formed by cells that form tissues.

Several tissues form organs, and some organs working together form a system.

Human being uses some systems to carry out the vital functions: 1.1.- Nutrition: is the process in which living beings get oxygen and nutrients, that they use to get energy and grow. Later they expel waste products.

1.2.– Interaction: is the process in which living beings gather information from the environment and produce different reactions.

1.3.– Reproduction is the process in which living beings produce more beings similar to themselves.

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NUTRITION SYSTEMS are: .– Digestive system. .– Respiratory system. .– Circulatory system. .– Excretory system.

INTERACTION SYSTEMS are:

1.– Sense organs: Sight, hearing, smell, taste and touch.

2.– Nervous System: Central and peripheral nervous system.

3.– Locomotor System: Skeleton and muscles.

2.– INTERACTION FUNCTION. During a normal day, we get millions of pieces of information from outside and inside of our bodies. We have to filter them and choose the most important ones.

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Our receptors (sense organs) gather stimuli, and send signals through the nerves to our brain (nervous system). The brain study the information and give a response (to our locomotor system) to react.

Finally our muscles generate the movement.

Activity: Look at this man and the driver. What are the stimuli and the responses in each case?. Explain it SENSE ORGANS

gather

information from the

3.– OUR SENSES. environment, and send it to the brain through the nerves.

There are some organs related with the five senses: The eye (sight), the ear (hearing), the nose (smell), the tongue (taste) and the skin (touch).

These organs have got sensory receptors (specialised cells to detect stimuli from the environment) to gather information. Connected with these receptors, there are nerves to send signals to our brain.

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USEFUL WORDS: .– sense organs .– locomotor system .– stimulus .– sight .– smell .– touch

.– nervous system .– response .– stimuli .– hearing .– taste .– sensory receptors

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Eyes detect light and images around us, change them into electrical signals and send them to the brain.

3.1.– EYES AND SIGHT. Eyes are the sense organs of sight.

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Eyebrow Eyelashes

Lachrymal glands

PARTS OF THE EYE: 1.– OUTER PARTS: .– Eyebrow: protect eye from sweat. .– Eyelashes: hairs that protect the eye. .– Eyelid: skin that cover and protect the eye. .– Iris: the coloured part of the eye.It expands and contracts to control the light. .– Pupil: the hole in the centre of the iris. It is black. .– Cornea: the front part of the sclera. It’s transparent. .-Lachrymal glands: produce tears to moist the eye.

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1.– INNER PARTS: .– Lens: it is transparent, and focuses light on the retina. (like the lens of a camera). .– Vitreous humour: a thick liquid. .– 3 layers: Sclera: the white layer.

Choroid Retina: with receptor cells, that convert images into electric signals. .– Optic nerve: transports signals to the brain.

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Process of sight: the image enters through the cornea, the pupil, and lens. Lens focuses the image on the retina where the receptor cells change it into signals. These signals are sent through the optic nerve to the brain .

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Protect your sight: Remember: you must protect your sight from outer conditions.

1.– Do not spend too much time in front of a screen, and do not sit too close to it.

2.– Read or do your homework in a place plenty of light.

3.– Be careful with sunlight.

4.– When something (dust, sand…) gets into your eye, wash your eye with water.

5.– If you can’t see properly, go to the doctor.

USEFUL WORDS: OUTER PARTS of the eye: .– eyebrow .– eyelashes .– eyelid .– lachrymal gland INNER PARTS of the eye: .– lens .– vitreous humour .– optic nerve

.– iris .– pupil .– cornea

INTERACTIVE ACTIVITIES:

.– 3 layers: .– sclera .– choroid .– retina

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3.2.– EARS AND HEARING. Ears are the sense organs of hearing.

Middle ear

Outer ear Pinna

Malleus (hammer)

Incus (anvil)

Stapes (stirrup)

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Inner ear Semicircular canals

Cochlea

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Eustachian tube

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Ear drum

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PARTS OF THE EAR: Ears detect sound vibrations around us, change 1.– OUTER EAR: .– Pinna: gather vibrations. them into movements (ossicles and cochela) and .– Auditory canal: is a tube. finally into electric signals that are sent to the brain.

2.– MIDDLE EAR: .– Eardrum: is a membrane to transmit vibrations.

Ears assist with balance too. .– Chain of ossicles: transmit the vibrations.

They are three: .– Malleus. .– Incus. .– Stapes .– Eustachean tube: connected with the throat.

3.– INNER EAR: .– Cochlea: with receptor cells inside for hearing. .– Semicircular canals: with receptor cells for movement. .- Auditory nerve: to send signals to the brain..

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Process of hearing: vibrations go through the pinna and auditory canal to the eardrum. The eardrum transmits the vibrations to the ossicles and to the receptor cells in the cochlea that change them into signals.

These electric signals are sent through the auditory nerve to the brain.

Balance: in the semicircular Canals, there are receptor cells that detect position and movement that change into signals and send them to the brain.

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USEFUL WORDS: OUTER EAR: .– pinna .– ear canal MIDDLE EAR: .– eardrum .– chain of ossicles: .- malleus .– incus .– eustachean tube INNER EAR: .– cochlea .– semicircular canals .- auditory nerve

.– stapes

Protect your hearing: Remember: you must protect your ears from outer conditions. .– Do not listen music too loud, or do not use headphones for a long period of time. .– Avoid very loud noise. .– Do not insert objects into your ears. .– If you do not hear properly, or your ears hurt, go to the doctor.

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3.3.– SKIN AND TOUCH. Skin is the organ of touch. Skin is the biggest organ of our body.

Skin is a layer that protects our body. It has millions of nerve endings that detect pressure, pain and temperature.

Skin sends electrical signals with this information to the the brain.

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Process of touching: in the skin there are millions of receptor cells that detect pressure, pain and temperature. They send these signals through the nerves to the brain.

Protect your skin: Remember: you must protect your skin from outer conditions. .– Wash your hands frequently and have a shower every day. .– Protect your skin from the sun with a sunscreen. .– Do not stay under the sun for a long period of time.

Sunlight can produce Skin Cancer.

3.4.– NOSE AND SMELL. Nose is sense organ of smell.

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Nose detects different molecules in the air. Nose has got receptor cells (in the olfactory epithelium), and they change information into signals that go to the brain through the olfactory nerve.

Olfactory nerve

INNER COMPONENTS OF NOSE: .– Nasal cavity: is the space inside the nose. .– Olfactory epithelium: is the surface inside the nose with nerve endings that have millions of receptor cells. .– Olfactory nerve: sends olfactory information to the brain.

Process of smell: the receptors in epithelim detect different molecules in the air. This information is changed into signals that the olfactory nerve sends to the brain.

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SKIN .– pressure .– pain .– temperature .– epidermis .– dermis .– sensory nerves .– capillaries .– sunscreen .– sebaceous gland .- sweat glands .– skin cancer

Protect your nose: .– Clean your nose. If you have a cold you can wash your nasal cavity with salted water. .– Do not insert objects into your nose. .– Do not smell dangerous substances.

NOSE .– nasal cavity .– olfactory epithelium .– olfactory nerve

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3.5.– TONGUE AND TASTE. Tongue has got taste buds. Taste buds are the sense organs of taste.

Tongue has got thousands of taste buds. They have got receptor cells that detect the substances in the mouth, change this information into signals and send them to the brain.

Taste buds

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The tongue has got four types of taste buds so it can detect four different flavours: .– Bitter like coffe. .– Sour like lemon. .– Salty like salt. .– Sweet like honey.

Process of tasting: in the tongue there are taste buds with receptor cells. Taste buds detect molecules from food, change this information into signals and send them through the gustatory nerve to the brain.

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Protect your taste: .– Clean your teeth three times a day. (And your nose, because smell and taste work together). .– Be careful with very hot and very cold food (you can burn your tongue) .– Go to the dentist.

4.– NERVOUS SYSTEM. Nervous system receives impulses from stimuli from outside and inside the body, analyses this information, and gives responses to it.

BITTER

SOUR SALTY

SOUR SALTY

SWEET 4

The nervous system is a net of specialized cells called neurons, that receives information, coordinates actions and transmits signals between different parts of the body.

It controls voluntary actions (walking , running…) and involuntary actions and systems (breathing, heart pumping, digestive system…).

Nervous system has two parts: the central nervous system and the peripheral nervous system.

The nervous system consists of specialised cells called neurons.

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TASTE: .– tongue .– taste buds .– bitter .– sour .– salty .-sweet

NERVOUS SYSTEM: .- central nervous system. .– peripheral nervous system. .– neurons .– cell body .– axon .– dendrites

Neurons are the specialized cells in the nervous system. They have a cell body, one axon and many dendrites.

4.1.- NEURONS. Parts of neurons: .- Cell body with a nucleus. .- Axon: It is the longest part of the neuron. It sends chemical and electric impulses to other neurons. A neuron has got only one axon. .- Dendrites: they are like branches connected with other neurons. They receive chemical and electric impulses from axons from other neurons.

These electric impulses from one neuron to another one are called synapses.

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4.2.– CENTRAL NERVOUS SYSTEM. A.– THE BRAIN is formed by cerebrum, cerebellum and brain stem. It is protected by the skull.

A1.– Cerebrum is the largest part of the brain. It gets information from the sense organs and controls: senses, intelligence, thinking, language, memory and takes decisions...

The central nervous system is composed by the brain and the spinal cord.

The brain is composed by cerebrum, cerebellum and brain stem.

Parts of the brain.

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Cerebrum

A.2.–Cerebellum coordinates voluntary movements, balance...for walking, etc.

A.3.– Brain Stem connects the cerebrum with the spinal cord, and controls automatic movements (heart, breathing, digestive system, blood pressure…)

B.– SPINAL CORD connects the brain and the peripheral nervous system, and transports information between them. It is protected by the spinal column.

It is the responsible for the involuntary responses or reflexes, that permit us to react very quick without thinking.

For example, if we cut or burn a finger, we remove it very fast.

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4.3.– PERIPHERAL NERVOUS SYSTEM It is formed by the nerves. They are like cables that link the central nervous system with the rest of the body (organs, sense organs, muscles…).

Cerebellum

Brain Stem

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There are two types of nerves: .– Sensory nerves that send information from the sense organs to the brain. .– Motor nerves that send information from the brain to the rest of the body.

Peripheral nervous system is made up of nerves, and links the central nervous system with the rest of the body.

There are two types of nerves: sensory nerves and motor nerves.

Protect your nervous system: .– Avoid substances like alcohol and other drugs. .– Protect your body against accidents (wear a helmet when you ride a bike)...

USEFUL WORDS:

.– Central nervous system:

.– brain .– cerebrum .– cerebellum .– brain stem .– spinal cord

.– Peripheral nervous system:

.– sensory nerves .– motor nerves

Nervous system.

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5.– LOCOMOTOR SYSTEM:

The locomotor system is formed by skeleton and muscles.

5.1.– SKELETON: Skeleton is a structure formed by bones and joints. long bone (femur)

Functions of skeleton: .– Skeleton supports the body. .– Skeleton protects our most important organs. .– Skeleton makes possible the movement of the body.

A.– BONES: Bones are hard pieces that form the skeleton.

They are hard because they contain lots of minerals, and light because of their spongy structure.

Types of bones: .– Long bones like femur, humerus .– Short bones bones from the wrist. .– Flat bones like bones from skull.

Flat bone (skull) short bone (wrist) 2

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HEAD: skull mandible mandible

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B.– JOINTS: 5 Joint is the place where two bones link one to another.

In joints there are ligaments (that join bone to bone), tendons (that join muscles to bones), and cartilages (to protect bones from friction).

TRUNK: clavicle clavicle scapula scapula sternum sternum

Types of joints: .– Mobile joints: with a big capacity of

ARM:

movement (shoulder).

humerus radius

.– Semi-mobile joints: with a reduced mobility (joint between two vertebrae).

ulna

ribs ribs Spine: spine vertebrae pelvis pelvis coccyx coccyx

carpals

.– Immovable joints: with no mobility (bones of the skull).

metacarpals

phalanges

C.- LESIONS OF BONES AND ARTICULATIONS Most frequent injuries are: .- Bone fracture: when a bone breaks. .- Sprain: it is an excessive stretching, tear or fracture of a ligament. .- Luxation: it is when bones are not in their habitual place.

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USEFUL WORDS: .– bone .– joint .– short bones .– flat bones .– tendon .– cartilage .– semi-mobile joint .– bone fracture .– luxation

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LEG:

femur

patella tibia fibula tarsals

.– long bones .– ligament .– mobile joint .– immovable joint. .– sprain

metatarsals phalanges

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5.2.– MUSCULAR SYSTEM: Our muscular system is formed by muscles and tendons. Muscles are connected to the skeleton by tendons, so when a muscle contracts, it moves a bone and produces a movement.

Muscles are formed by muscle cells. These cells can contract (they become shorter) when they receive nerve signals from the brain. When the signals stop, these cells relax, and return to their original length (the muscle relaxes and elongate).

Muscles need a lot of energy supplied by blood (oxygen, glucose and other nutrients), and blood also removes waste products from them.

Our muscular system is formed by muscles, and tendons. Muscles move the skeleton. They are formed by muscle cells that can contract and relax.

Blood vessel

Bone

Muscle fiber

Group of fibers

Tendon

Structure of a skeletal muscle.

A.– TYPES OF MUSCLES:

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1.- Smooth muscles: we can’t control them, (their movements are involuntary). They are in our digestive system, blood vessels…

2.- Cardiac muscles: they form our heart. Their movement are very strong, and they are working before our birth till the day we die.

3.- Skeletal Muscles: they form our muscular system.

They are joint to our bones and their movements are voluntary (we can control them). Their fibers are very long, and our brain can give orders to them.

There are three types of muscles: Smooth muscles, cardiac muscles and skeletal muscles.

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B.– HOW OUR MUSCLES WORK: If a muscle contracts, moves a tendon held to a bone and produces a movement.

There are always two opposite muscles (antagonist muscles) for example biceps to bend and triceps to stretch the arm.

C.– PROTECT YOUR LOCOMOTOR SYSTEM: .– Sit down or stand with your back straight, it will be good for your spine. .– Keep your back straight and bend your knees when you want to lift heavy objects. .– Do some physical activity regularly, but don’t forget to warm up before to do it.

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USEFUL WORDS: .– muscle cells (or fibers) .– to contract .– smooth muscles .– antagonist muscles

.– tendons .– to relax .– cardiac muscles .– skeletal muscles

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masseter sternocleidomastoid

Orbicularis oculi

HEAD & NECK: .– masseter .– orbicularis oculi .– sternocleidomastoid

deltoid

pectorals trapezius

biceps triceps Latissimus dorsi Intercostal muscles

Gluteal muscles

Abdominal muscles sartorius

bíceps femoris

quadriceps calves ARM: .– deltoid .– bíceps .– triceps

Achilles tendon

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TRUNK: .– pectorals .– abdominal muscles. .- Intercostal muscles. .– trapezius .– latissimus dorsi

LEG: .– gluteal muscles .– bíceps femoris .– quadriceps .– sartorius .– calves .– Achilles tendon

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