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- 2 lungs
- Set of tubes
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- Thoratic cavity
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- Take in oxygen
- Release carbon dioxide and water vapour
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- Allows air into the nose
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- Warms air
- Filters air by mucus
- Moistens air
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- Prevents food being swallowed into trachea
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- Makes noise
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- Allows air to pass to lungs
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- Keeps trachea open
- Keeps bronchi open
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- Transports air into lungs from trachea
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- Transports air to alveoli
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- It is the site of gaseous exchange
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- Tiny, hollow, balloon like air sacs
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- Thin walled
- Moist
- Numerous
- Rich blood supply
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- Oxygen moves from alveoli to capillaries by diffusion
- Combines with haemoglobin and becomes oxyhaemoglobin
- RBC carry oxyhaemoglobin around to all body cells and releases oxygen when required
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- Moves from plasma to alveoli by diffusion
- Then excreted through the lungs
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- Involuntary process
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- 15 times per minute
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- Brain controls rate of breathing
- It sends a message to intercostal muscles and diaphragm
- These muscles use energy to contract
- Intercostal muscles contract and rib cage moves up and out
- Diaphragm contracts and moves down
- Volume in the lungs increases
- Pressure in the lungs decreases
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- Active Process
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- It requires energy
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- Intercostal muscles relax, rib cage moves down and in
- Diaphragm relaxes and moves up
- Volumes in lungs decreases
- Pressure in lungs increases
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- Passive Process
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- It does not require energy
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- Athsma
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- Narrowing of bronchioles
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- Breathlessness
- Wheezing
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- Exposure to allergens
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- Dust
- Pollen
- Animal or plant dander
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- Avoid known allergens
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- Use an inhaler
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- Widens bronchioles
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- Breathing is controlled by the medulla oblongata in brain
- Cells in this area are sensitive to pH of blood
- CO2 lowers pH of blood
- Creating an acidic environment
- Increases in CO2 stimulates intercostal muscles and diaphragm
- Results in an increase in breathing rate to get rid of excess CO2