Which one of these factors would decrease the diffusion of a gas across the alveolar/pulmonary capillary membrane?
A)an increase in thickness of the membrane
B)an increase in surface area of the membrane
C) an increase in the partial pressure gradient
D) the gas's smaller molecular size

Question

Quizplus · Accepted Answer

An increase in the thickness of the alveolar/pulmonary capillary membrane would create a longer distance for the gas to travel, which would decrease the rate of diffusion. The other factors listed (an increase in surface area, an increase in partial pressure gradient, and a smaller molecular size of the gas) would all increase the rate of diffusion.

Which One of These Factors Would Decrease the Diffusion of a Gas