Question

Why don't alveoli collapse even after forceful expiration?

Answer 1

Alveoli:

1. Alveoli are thin, vascularized, bag-like structures with irregular walls.
2. They are the sites of gaseous exchange.
3. It is where the actual diffusion of gases occurs.

Residual volume:

1. Residual volume is the volume of air, which remains in the lungs even after forceful expiration.
2. Due to residual volume, alveoli do not collapse even if we do a forceful expiration.
3. The value of the average residual volume is around 1100 ml to 1200 ml.