Gaseous Exchange in the Alveoli

Question 1

What are the alveoli?

Answer 1

The respiratory surface of the lungs

They are full of air and are covered on the outside by blood capillaries

Question 2

What does oxygen do?

Answer 2

It diffuses across the walls of the alveoli from the air into the blood

Question 3

What does carbon dioxide do?

Answer 3

It diffuses across the walls of the alveoli from the blood into the air in the alveoli

Question 4

What 4 things make the alveoli adapted foe gaseous exchange?

Answer 4

1. Good blood supply, so that more gases can be exchanged (Red blood cells carry oxygen)
2. Large surface area - increases gaseous exchange
3. Thin walls - gases can pass through diffusion much easier
4. Moist lining to dissolve oxygen so that it can diffuse through the alveolus wall