What roles do sodium and potassium play in cell function?

Question

What roles do sodium and potassium play in cell function?

Answer 1

voltage gated ion channels

Answer 2

Without getting too fancy, there's an electrochemical gradient across the phospholipid bilayer.  When there are electrolyte derangements, a lot of odd things happen.  An animal cell has a special method of ensuring (physiologically) that the concentration of sodium inside or outside the cell are kept at a proper levels.  When the cell is deprived, i.e. decreased perfusion, there is a shut-down of the Na-K ATPase and as a result there's swelling of the cell and necrosis (cytotoxicity).  In neurons or myocardial cells, it becomes even more complicated when we talk about action potentials but that's beyond the scope of this discussion.

In short, if the cells is working properly, the concentration of intrcellular Na & K has to be held to appropriate levels, otherwise there can be catastrophic consequences for the cell and for the organ.