The Slightly Lower PH of Venous Blood Compared to Arterial

Question

The slightly lower pH of venous blood compared to arterial blood is caused by
A) the lower oxygen level of venous blood
B) the influx of lactic acid in venous blood
C) the influx of carbon dioxide in venous blood
D) all of the above

Accepted Answer

The influx of carbon dioxide in venous blood leads to a slightly lower pH, as carbon dioxide reacts with water to form carbonic acid, which lowers the pH of the blood. The lower oxygen level in venous blood and influx of lactic acid can also contribute to acidity, but carbon dioxide has the most significant effect on pH.