All of the Following Decrease the Rate of Gas Exchange

Question

All of the following decrease the rate of gas exchange during external respiration EXCEPT
A)emphysema
B)increased alveolar PO2
C)increased altitude
D)pneumonia
E)increased alveolar PCO2

Accepted Answer

Increased alveolar PO₂ (partial pressure of oxygen) would actually increase the rate of gas exchange during external respiration. The other choices, emphysema, increased altitude, pneumonia, and increased alveolar PCO₂ (partial pressure of carbon dioxide), can all decrease the rate of gas exchange during external respiration.