Question

Diffusion of oxygen occurs in the alveolar region only and not in the other parts of respiratory system how do you justify the statement?

Answer 1

Explanation:

The venous blood that reaches the alveoli has lower partial pressure of O2 and higher partial pressure of CO2 as compared to alveolar air. Hence, oxygen diffuses into blood. Simultaneously, carbon dioxide diffuses out of blood and into the alveoli.