Question

question 24
which of the following might allow diffusion of gases in the lung to occur faster?
a decreasing the gas exchange diffusion distance
b decreasing the surface area
c decreasing the rate of breathing
d decreasing the depth of breathing

Explanation:

According to Fick's law of diffusion, the rate of gas diffusion ($\dot{V}_\text{gas}$) is given by the formula $\dot{V}_\text{gas}=\frac{D\times A\times(P_1 - P_2)}{T}$, where $D$ is the diffusion constant, $A$ is the surface area, $(P_1 - P_2)$ is the partial - pressure difference, and $T$ is the thickness (diffusion distance). A decrease in diffusion distance ($T$) would increase the rate of gas diffusion. Decreasing the surface area ($A$) (Option B) would decrease the rate of diffusion. Decreasing the rate of breathing (Option C) and decreasing the depth of breathing (Option D) would reduce the ventilation, which in turn would reduce the partial - pressure difference ($P_1 - P_2$) and thus the rate of gas diffusion.

Answer:

A. Decreasing the gas exchange diffusion distance