Question

What is the pH range of intracellular fluid?

(a) 7.0 to 7.2

(b) 7.3 to 7.35

(c) 7.35 to 7.45

(d) 7.50 to 7.60

I had been asked this question during an interview for a job.

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

Answer 1

Correct answer is (a) 7.0 to 7.2

For explanation: 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. It is quite difficult to measure the pH of fluids inside the tissue cells, but from estimates based on CO2 and (HCO–3) ion concentration, intracellular pH probably ranges from 7.0 to 7.2.