Question

which of the following is the relative concentration of gases in alveolar air?
a.) nitrogen > carbon dioxide > water vapor > oxygen
b.) oxygen > nitrogen> water vapor > carbon dioxide
c.) nitrogen > oxygen > water vapor > carbon dioxide
d.) oxygen > water vapor > nitrogen > carbon dioxide

Explanation:

Alveolar air contains nitrogen as the most abundant gas (similar to atmospheric air, but with some exchange). Oxygen is present but less than nitrogen. Water vapor is significant due to the moist respiratory tract. Carbon dioxide is the least abundant among these in alveolar air compared to the others listed.

Answer:

C. nitrogen > oxygen > water vapor > carbon dioxide