Our bodies must maintain a stable pH and H+ ion concentration.
The normal concentration of H+ in the extracellular body fluid ranges from 36–44 nmol/L, but the body produces much greater quantities of H+.
Via the lungs and kidneys, the body controls and excretes H+ to maintain pH homeostasis.
The Henderson-Hasselbalch equation is a formula for determining plasma pH.
In this equation, the base is HCO3- and the acid is H2CO3. pKa has a constant value of 6.1.
With an HCO3-/H2CO3 ratio of 20/1, a normal plasma pH will be 7.4.
