Lungs and Gas Exchange - Organisation P2

Question 1

What does the diaphragm do?

Answer 1

contracts to increase the volume of the chest

Question 2

What does the aleveoli do?

Answer 2

increase surface area of the lung to maximise gas exchange

Question 3

What does the lung do?

Answer 3

organ in which gas exchange takes place

Question 4

What do the intercostal muscles do?

Answer 4

contract to pull the ribcage up and outwards

Question 5

What does the trachea do?

Answer 5

carries air to and from the lungs

Question 6

What does the bronchi (bronchus) do?

Answer 6

carries air into the left or right lung

Question 7

What do the bronchioles do?

Answer 7

carry air to the alveoli

Question 8

What does the ribs do?

Answer 8

Protect the lungs and heart

Question 9

What changes occur to the chest cavity when breathing in?

Answer 9

• Intercostal muscles contract - the rib cage moves up/outwards
• At the same time diaphragm muscles also contract and move down
• This increases the size of chest cavity - lower pressure allows air to move in because of the pressure difference

Question 10

Why are there rings of cartilage on the trachea?

Answer 10

It prevents the trachea from collapsing during inhalation

Question 11

What adaptations do alveoli have so that the rate of gas exchange happens fast?

Answer 11

• Millions of alveoli - lungs have a huge surface area
• very thin walls - diffusion happens easily
• good blood supply

Question 12

What happens when we exhale?

Answer 12

• The intercostal muscles relax and pull the rib cage down and in
• The diaphragm relax and moves upwards
• This decreases the pressure
• Air is expelled from the body

Question 13

Explain gas exchange

4 steps

Answer 13

1. The alveoli contains air that has a high concentration of oxygen and low concentration of carbon dioxide
2. Oxygen will therefore diffuse into the blood
3. Carbon dioxide with diffuse out of the blood, down the concentration gradient.
4. The blood is oxygenated and is pumped around the body for cells to respire

Question 14

Explain gas exchange

4 steps

Answer 14

1. The alveoli contains air that has a high concentration of oxygen and low concentration of carbon dioxide
2. Oxygen will therefore diffuse into the blood
3. Carbon dioxide with diffuse out of the blood, down the concentration gradient.
4. The blood is oxygenated and is pumped around the body for cells to respire