If alveolar surface area is decreased 50% and pulmonary edema leads to a doubling of diffusion distance, how does diffusion of oxygen compare with normal?
A)25% increase
B)50% increase
C)25% decrease
D)50% decrease
E)75% decrease

Question

Quizplus · Accepted Answer

The diffusion of oxygen is directly proportional to the surface area and inversely proportional to the diffusion distance. A 50% decrease in alveolar surface area and a doubling of diffusion distance would lead to a 75% decrease in oxygen diffusion, as per the formula for diffusion capacity (Vgas = A/T * D * (P1 - P2)), where A is surface area and T is thickness or diffusion distance.

If Alveolar Surface Area Is Decreased 50% and Pulmonary Edema