Sodium and potassium
Sodium and potassium both are very important for human body and regulate the water
balance and the acid base balance in the blood and tissue (Beers & Berkow 1997). The major
intracellular cation is potassium, with an average concentration of 140 m Eq/l. The extracellular
potassium concentration, though very important and tightly regulated, is much lower,
at 3.5 – 5 m Eq/l. The major extra-cellular cation is sodium, with an average concentration
of 140 m Eq/l. Intracellular concentration sodium concentration is much lower at about
12 m Eq/l. These differences are maintained by the Naþ, Kþ-ATPase ion pump located in the
cell membranes of virtually all the cells (McCarron no date).