Question

The venous blood pH falls to approximately 7.36.

(a) True

(b) False

I have been asked this question in unit test.

This interesting question is from Spirometry topic in chapter Pulmonary Function Analysers of Biomedical Instrumentation

Answer 1

Right option is (a) True

To explain I would say: True, as venous blood acquires carbon dioxide, forms carbonic acid and hydrogen ions, the venous blood pH falls to approximately 7.36. This pH drop of 0.04 units occurs when the CO2 enters the tissue capillaries. When CO2 diffuses from the pulmonary capillaries into the alveoli, the blood pH rises 0.04 units to bring the normal arterial value of 7.40.