ABSTRACT
The normal plasma concentration of sodium is 140mmol l−1, whereas that of H+ is 0.00004mmol l−1. Thus, H+ concentration is represented as pH, which is the negative log10 of the H+ concentration. The normal extracellular pH is 7.4, venous blood 7.35, red blood cells 7.2, muscle cells 6.8-7.0 (in anaerobic metabolism 6.40) and that of CSF 7.32.
