Which of the Following Does Not Directly Assist in the Exchange

Question

Which of the following does not directly assist in the exchange of gases between blood and the air?
A) thin walls of the alveoli
B) thin walls of the capillaries in the lung
C) viscosity of the respiratory mucosa
D) alveolar surface area

Accepted Answer

The viscosity of the respiratory mucosa does not directly assist in the exchange of gases between blood and air. The other options listed, thin walls of the alveoli, thin walls of capillaries in the lungs, and alveolar surface area all play a critical role in facilitating gas exchange between the blood and air in the lungs.