◄UNIT 11:Circulatory SystemUnit 13 Reproduction system►

UNIT 12 :Respiratory System

  • UNIT 12 :Respiratory System

    1. Look at the picture below.

    x

    2. Is it right or wrong to smoke inside the house where people are?
    3. How does smoke affect the health of people?
    4. What would you advise people who smoke in public places?

    5. Predict what you are going to learn in this unit.

    12.1 The human respiratory system and its function
    Find out
    1. The main function of human respiratory system .

    2. The various organs of the human respiratory system.

    Activity 12.1 Investigating the main function of the
    respiratory system
    1. Take a deep breathe and note the time on the clock or wrist
    watch.
    2. Close your mouth and nose tightly and hold onto your breathe.
    How long can you stay without breathing? What does this tell
    you about breathing?

    The main function of respiratory system is to transport fresh air(
    oxygen) into the lungs and remove waste air (carbondioxide) out of the lungs.

    I    dentification of organs of the respiratory system
    Activity 12.2 Identifying organs of the respiratory system
    1. Look at the picture below.

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    2. Draw and label the human respiratory system in your notebook.

    The main parts of the human respiratory system are the nose,

    trachea lungs (windpipe), bronchi and the diaphragm.

    k

    Table 12.1: Parts of respiratory system and their functions

    j

    e

    12.2 Mechanism of respiration (Breathing in and out)
    Find out
    1. How the human respiratory system operates.

    2. The process of breathing in and breathing out in human beings.

    Activity 12.3    Investigating the mechanism of the
                             respiratory system 
    1. Place your hands on both sides of your chest. Take a deep breath.
    What happens to your chest?
    2. Repeat this several times and note what happens.

    3. Interpret your findings about breathing process.

    Activity 12.4    Experiment to demonstrate how
                             respiratory system works
    What you will need
    Bell jar, two balloons, rubber stopper, Y-shaped glass tube, rubber sheet,
    string.

    1. Set up the things above as shown in the picture below.

    s

    2. What do you think the following parts represent in the respiratory
    system?
    a) Bell jar
    b) Balloons
    c) Rubber sheet
    d) Y-shaped tube
    3. Pull down the string tied on the rubber sheet. What happens to
    the balloons?
    4. Release the string. What happens to the balloons?
    5. Repeat steps 3 and 4 several times as you note what happens.
    6. How do you think the findings in this experiment relate to the

    working of the breathing system?

    Mechanisms of breathing
    Respiration refers to the act of breathing in / inhalation / inspiration

    and breathing out/ exhalation / expression.

    • The bell jar represents chest cavity, Y-shaped tube represents the
    trachea and bronchi, the balloons represents the lungs and the rubber
    sheet represents the diaphragm.

    Breathing in ( inhalation/ inspiration)
    • When the rubber sheet is pulled downwards, the volume inside the
    bell jar increases.
    • The balloons become inflated( air rushes into the ballons). This is

    similar to what happens during breathing in.

    h

    • When the sheet is released, the volume inside the bell jar reduces.
    Air is pushed out of the balloons and they become deflated. This is similar to what happens during breathing out.

    h

    Table 12.2: What happens during (inhalation) and breathing out

    (exhalation)

    j

    12.3 Good health practices and behaviours for a
    healthy respiratory system
    Find out

    1. Care of the respiratory system.

    Activity 12.5 Experiment to demonstrate the
    danger of smoking cigarette
    What you will need
    • Transparent plastic bottle with cap
    • Tissue paper              • Rubber band
    • Cigarette                    • Match box
    • Nail                            • Biro-pen casing with cap
    • Water
    1. Make a hole at the bottom of the plastic bottle. Insert the biro

    pen casing as shown below. Ensure that the bottle top is on.

    k

    2. Fill the bottle almost three-quarter way with water.
    3. Take the cap off the bottle, make a hole then insert the piece of

    cigarette.

    h

    4. Screw the bottle cap into the bottle with the cigarette filter inside
    the bottle.
    5. Light the cigarette using the match stick and match box.
    6. Remove the cap of the biro pen casing to let the water out as

    shown below and observe what happens.

    h

    7. Once all the water is drained out of the bottle, remove the bottle
    cap and wrap the tissue paper round the mouth of the bottle. Tie
    it using the rubber band.
    8. Blow air through the biro pen using the bottom of the bottle as

    shown below.

    f

    Why do you think this is important?
    9. Unwrap the tissue paper and observe it carefully. What can you
    see?
    10. Discuss the results of this experiment with your friends. Relate
    your findings here to what happens to the lungs when you smoke.
    11. Based on the results of this experiment, do you think smoking is good or bad for our health?

    Ways of taking care of the respiratory system include:
    • Avoiding smoking or excessive driving of alcohol to
    ensure healthy lungs.
    • Eating a vitamin- rich diet
    • Seeking immediate medical care in case of a respiratory problem.
    • Exercising regularly to strengthen respiratory muscles.
    • Drinking plenty of water.
    • Avoid refined sugar, pasta or dairy products.
    • Avoiding inhaling unknown or dangerous substances or
    chemicals.
    • When spraying chemicals in the house or any other place,
    always wear protective clothing, for example, a gas mask.

    • Developing good eating habits

    12.4 Diseases of the respiratory system
    Find out
    1. The various diseases that affect the respiratory system.

    2. What are their signs and symptoms?

    Activity 12.6 Investigating the diseases of the
                         respiratory system 
    1. Using search engine, find out about diseases of the respiratory
    system.
    2. Write down your findings in your exercise book.
    Common diseases of the respiratory system include:
    • Tuberculosis (TB)
    • Whooping cough
    • Asthma
    • Bronchitis

    • Pneumonia

    Table 12.3 Signs and symptoms of the respiratory diseases and their

    control measures

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    x

    12.5 Suffocation
    Find out
    1. What suffocation is.
    2. The cause of suffocation.

    3. First aid for suffocation.

    Activity 12.7 Investigating the causes and
    first aid suffocation

    1. Look at the picture below.

    k

    2. Discuss what happened to the people in the picture above.
    If a person does not get enough air into the lungs, he/she suffocates.
    Note: Suffocation may lead to death.

    a) Causes of suffocation
    • Choking - this is the blocking of the windpipe by food or other
    materials. It prevents smooth flow of air into the lungs.
    • Drowning – when we drown, the water prevents air from
    reaching our lungs. We therefore suffocate.
    • Carbondioxide inhalation.
    • When a place is so hot that you cannot breathe easily you may

    suffocate.

    h

    b) First aid for suffocation
    In case of suffocation, you should do the following:
    • For all the victims, loosen the clothing surrounding the neck, move
    the victim to an open place with plenty of fresh air.
    • Gently slap between the shoulder blades in case of chocking.

    • Perform abdominal thrusts.

    s

    • If the person is unconscious, lie them on a flat floor, clear the airways
    and perform chest compressions.
    • In case of drowning, tilt the victim towards one side with the head
    down.
    • If breathing has stopped, mouth to mouth resuscitation should be

    given.

    Self –Test 12.1
    1. Which four practices would help to prevent respiratory problems
    in human beings?
    2. Name four respiratory diseases.
    3. What causes suffocation?

    4. Describe the procedure you will use to help a suffocated person.

    UNIT TEST 12
    1. A human being without a respiratory system is as good as a car
    without fuel. Explain this statement.
    2. Explain the following observations:
    a) Your heart rate increases when you do exercise such as running.
    b) You cannot hold your breathe for more than five minutes.
    3. Describe what happens to the chest and lungs during:
    a) breathing in.
    b) breathing out.
    4. Dust particles and germs are trapped by the _______ and
    ___________ in the nostrils. Why is this important?
    5. The _______________ is a sheet of muscles that separates the
    chest cavity from the abdomen.
    6. What do the parts shown in the breathing model below represent

    in human respiratory system?

    g

    7. During breathing out, the waste gas called _____________
    moves from the blood into the air sacs, after which it is breathed
    out. On the other hand ______________ gas moves from the air
    inside the air sacs into the blood.
    8. Inspiration is to _________ as expiration is to __________
    9. Which one of the following organs is not involved in breathing?
    A. Diaphragm                           B. Bronchioles
    C. Oesophagus                        D. Wind pipe
    10. Describe an experiment you would use to show dangers of
    smoking to members of your class.
    11. How would you ensure that your respiratory system remains

    healthy.

    ◄UNIT 11:Circulatory SystemUnit 13 Reproduction system►