The Partial Pressure of Carbon Dioxide in Venous Blood Is

Question

The partial pressure of carbon dioxide in venous blood is approximately
A) 40 mm Hg.
B) 45 mm Hg.
C) 50 mm Hg.
D) 70 mm Hg.
E) 100 mm Hg.

Accepted Answer

The normal partial pressure of carbon dioxide in venous blood is approximately 45 mm Hg. This is due to the fact that carbon dioxide is produced as a waste product of cellular respiration, and is transported to the lungs via the bloodstream to be expelled. In the lungs, carbon dioxide diffuses from the blood into the alveoli, where it can be exhaled.