Why is it so important to keep the interior of the cells low in Na+ and high in K+?

It is essential to keep the interior of cells low in Na+ and high in K+ because of how the Na+K+ATPase pump functions. This pump regulates the concentration gradient in a manner in which the interior of cells are low in sodium and high in potassium. K+ leaks from the inside of the cell to the outside, generating a negative charge on the inside of the membrane. The concentration gradient must remain sustained for the necessary physiological processes in various organs. Additionally, the concentration gradient has a role in maintaining the resting membrane potential, as well as in signal transduction, regulating cell volume, and production of neuronal action potentials. If the interior of cells are unable to retain proper levels of sodium and potassium, the resting membrane potential would be disrupted and processes such as the propagation of action potentials would be affected.