Starter1. What is the name of

this cell?2. What is the main role

of this type of cell?3. This cell is “adapted” so it can carry

out its role very efficiently. Describe two such adaptations.

BREATHING

Breathing The primary function of breathing is to

supply the blood with oxygen

Oxygen is needed by every cell in the body to release the energy from glucose in a process called respiration.

Asthma

Anatomy of Breathing Oxygen enters the respiratory system

through the mouth and the nose.

The oxygen then passes through the larynx (voicebox) and the trachea; which is a tube that enters the chest cavity.

In the chest cavity, the trachea splits into two smaller tubes called the bronchi (singular = bronchus).

Anatomy of Breathing Each bronchus then divides again

forming smaller tubes called bronchioles.

The bronchioles lead directly into the lungs where they lead to tiny sacs called alveoli.

Alveoli They are spherical to

maxmise the surface area and have very thin walls

The average adult's lungs contain about 600 million of these spongy, air-filled sacs

The inhaled oxygen passes into the alveoli through and then diffuses through the capillaries into the blood.

Carbon dioxide from the veins is released into the alveoli and follows the same path out of the lungs when you exhale.

Alveoli

Gas exchange at the alveoliThe alveoli are bunches of tiny air sacks inside the lungs.

Each individual sack is called an alveolus.

When you breathe in, they fill with air.

The alveoli are covered in tiny capillaries (blood vessels).Gases can pass through the thin walls of each alveolus and capillary, and into the blood stream. Gases can also pass from the blood stream, into the alveolus.

Gas exchange at the alveoli

The Breathing System

The nasal passages and lungsAir is drawn into the body via the nose or mouth. There are advantages to breathing through your nose:

Air then travels through the larynx, trachea (windpipe), bronchi (one bronchus to each lung) and bronchioles to the alveoli, where oxygen passes into the bloodstream.

the air is warmed so that it is closer to body temperaturetiny hairs and mucus in the nose filter the air, preventing larger dust and pollen particles reaching the alveolimucus moistens the air, making it easier for the alveoli to absorb.

When you breathe in:

intercostal muscles between the ribs contract, pulling the chest walls up and outthe diaphragm muscle below the lungs contracts and flattens, increasing the size of the chestthe lungs increase in size, so the pressure inside them falls. This causes air to rush in through the nose or mouth.

Mechanisms of breathing – inspiration

Diaphragm contracts and moves down

Intercostal muscles pull ribs up and out

Mechanisms of breathing – expiration

When you breathe out:

Intercostal muscles between the ribs relax so that the chest walls move in and down.The diaphragm muscle below the lungs relaxes and bulges up, reducing the size of the chest. The lungs decrease in size, so the pressure inside increases and air is pushed up the trachea and out through the nose or mouth.Diaphragm

relaxes and bulges up

Ribs move in and down

Mechanisms of breathing – inspiration

Mechanisms of breathing – expiration

Aveoli are spherical (ball-shaped), have thin and moist walls, and surrounded by many capillaries. Explain why:

1) Aveoli are spherical

2) Aveoli have thin and moist walls

3) Aveoli are surrounded by many capillaries

Gas exchange at the alveoli

MRS GREN?

What is “respiration”?

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from the digestive system

from the breathing system

useful!waste product exhaled

waste product exhaled

This type of respiration is called aerobic respiration because energy is released with oxygen.

Respiration is the process that the body uses to release energy from digested food (glucose):

What is respiration?

carbondioxideglucose oxygen water energy

How do the glucose and oxygen needed for aerobic respiration get to the all the body’s cells?

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When the body is able to supply the cells with the oxygen and glucose that they need, it carries out aerobic respiration.

Anaerobic respirationWhen the body cannot supply the cells with the oxygen needed to break down glucose, then it has to carry out anaerobic respiration. Energy is released without oxygen:

Aerobic and anaerobic respiration

Aerobic respiration

carbondioxideglucose oxygen water energy

lacticacid energyglucose

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When anaerobic respiration takes place, the lactic acid produced soaks the muscle cells and prevents muscles from doing their job. This causes fatigue and sometimes cramp.

After activity that has lead to anaerobic respiration, the person involved pants and breathes heavily.

This happens because they need lots of oxygen to get rid of lactic acid that has built up in their body.

Not enough oxygen!

lacticacid energyglucose

carbondioxide

lacticacid oxygen water

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from the digestive system

from the breathing

system

useful!waste product exhaled

waste product exhaled

Respiration is the process that the body uses to release energy from digested food (glucose) by reacting it with oxygen.

What is respiration?

carbondioxideglucose oxygen water energy

1) What is respiration? Describe in words.

2) Write down the respiration equation.

3) Why do we breathe?

4) How is breathing different from respiration?

5) What is gas exchange?

Gas exchange at the alveoli

Inhaled air vs. Exhaled airGas Amount in

inhaled airAmount in exhaled air

Oxygen

Carbon dioxide

Nitrogen

Water vapour

17%

3%

79%

Large amount

21%

Very small amount

79%

Small amount

1) Find the differences2) Explain the differences

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Questions1. Why are there less oxygen and more carbon

dioxide in the exhaled air?2. Why is the amount of nitrogen unchanged?

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What are the differences between inhaled and exhaled air?

inhaled air

nitrogen (78%)oxygen (21%)carbon dioxide (0.04%)other

Comparing inhaled and exhaled air

How could you test for the differences between inhaled and exhaled air?

exhaled air

nitrogen (78%)oxygen (17%)carbon dioxide (4%)other

Practical – Air goes in, Air goes out

Practical – How much air can you breathe in?

Questions:1. What is the benefit of the lungs having tiny

air sacs rather than just one large structure?2. What process enables oxygen and carbon

dioxide to move across the alveolus wall?3. How is the alveolus wall adapted for

efficient movement of gas molecules?4. What is the name of the red pigment in

blood that bonds with oxygen?

The respiratory system and health

Why is a respiratory system that works properly essential for good health?

The respiratory system provides the body with the oxygen it needs for respiration.

The lungs are delicate, spongy organs that deal with 12,000 litres of air each day.

Smoking is a very dangerous habit that has serious effects on the lungs and respiratory system.

How does smoking damage health and fitness?

1) What is respiration? Describe in words.

2) Write down the respiration equation.

3) Why do we breathe?

4) How is breathing different from respiration?

5) What is gas exchange?

1) Write down the respiration equation (in words)

2) What are the three differences between inhaled air and exhaled air?

3) What would happen to the body if alveoli inside the lungs are filled with liquid?

Asthma

Bronchitis

Emphysema Caused by exposure to toxic

chemicals or long-term exposure to tobacco smoke.

Emphysema

How does smoking affect the lungs?

Which picture shows the healthy lungs of a non-smoker and which show the unhealthy lungs of a smoker?

healthy lungs smoker’s lungs

Not a difficult question to answer but some people still think that smoking is cool!

How does smoking affect health?

Effects of smoking on health

bronchitis

liver cancer

osteoporosis

mouth, lip andthroat cancer

asthma lung cancerdental hygieneproblems

facial wrinkles

pancreatic cancer

impairedimmune system

heart disease

cervical cancer

kidney cancer

sperm abnormalities and impotence

bladder cancer

leukaemia

emphysema

stomach cancertesticular cancer

menstrualproblems

Smoker’s cough

Make an anti-smoking poster for teenagers

Task