The PCO₂ in Alveolar Air is _____ Blood

Question

The PCO₂ in alveolar air is _____ blood.
A)less than in the systemic venous
B)greater than in the systemic venous
C)equal to the systemic arterial
D)Both A and C are correct.

Accepted Answer

The PCO₂ in alveolar air is less than in the systemic venous blood because CO₂ is being exhaled, but it is equal to the systemic arterial blood, as the arterial blood reflects the gas exchange that has occurred in the lungs.