Air Leaving the Lungs Has

Question

Air leaving the lungs has
A)a higher concentration of both oxygen and carbon dioxide than outside air.
B)a lower concentration of oxygen and a higher concentration of carbon dioxide than outside air.
C)equal concentrations of carbon dioxide and oxygen.
D)a lower concentration of oxygen and a lower concentration of carbon dioxide than outside air.

Accepted Answer

When air leaves the lungs, it has a lower concentration of oxygen and a higher concentration of carbon dioxide than outside air because oxygen diffuses into the bloodstream while carbon dioxide diffuses out of it in the lungs. Therefore, the air leaving the lungs has a lower oxygen concentration and a higher carbon dioxide concentration.