The site of gas exchange- alveolus

Question 1

What are the adaptive features of the alveoli in lungs?

Answer 1

1. Wall of alveoli is one-cell thick
2. Numerous alveoli: ~700 millions
3. The inner surfaces of the alveoli are covered with a water film
4. Richly supplied with blood capillary (network)

Question 2

Wall of alveoli is one-cell thick

Answer 2

1. To reduce the diffusion distance of gases

2. Rapid diffusion of gases

Question 3

Numerous alveoli: ~700 millions

Answer 3

1. Provides a very large surface area for gaseous exchange

2. Rapid diffusion of gases

Question 4

The inner surfaces of the alveoli are covered with a water film

Answer 4

1. Allow gases to dissolve
2. Gases diffuse more readily across the wall of air sac
3. rapid diffusion of gases

Question 5

Richly supplied with blood capillary (network)

Answer 5

1. Gases carried away from the alveoli by blood quickly
2. A steep concentraiton gradient of (O2/CO2) between air sacs and blood can be kepy
3. Rapid diffusion of gases