Solutes have an influence on the water distribution inside and outside the cell, exerting an osmotic pressure.
The sodium-potassium or Na+ -K+ ATPase pump is a transmembrane protein whose enzymatic activity uses energy derived from the degradation of ATP to ADP and inorganic phosphate to transport K+ and Na+ against their concentration gradient. It plays a role in maintaining the resting potential of nerve, muscle and cardiac cells. The pump is used to exchange sodium ions (Na +) from the intracellular medium with K + potassium ions from the extracellular medium in a precise ratio (3 Na + / 2 K +). This pump is responsible for restoring the initial balance after an action potential.
Although the sodium ore itself has an influence on the water distribution by exerting osmotic pressure, the action of the Na-K pump does not influence it directly, it will just keep the most of sodium ions outside the cell.
