What functions do the electrolytes do in the body (Part 2.) ?😤

This time will talk about the other important electrolytes in the body: 

Sodium

Na⁺ is the main cation in the extracellular fluid, and it plays a vital role in maintaining many important physiological activities in the body, such as maintaining the osmotic pressure of the extracellular fluid. 

Adult normal serum sodium is 135.0-145.0 mmol/L. Changing the concentration of Na⁺ in the extracellular fluid may caused by changes in the content of sodium and water, so sodium balance disorders are often accompanied by water balance disorders.

The balance of Na⁺ is mainly regulated by changes the volume of extracellular fluid and the concentration of plasma sodium. When the volume of extracellular fluid decreases or the concentration of plasma sodium decreases, it can activate the renin-angiotensin-aldosterone system to promote the reabsorption of Na⁺.

When the amount of extracellular fluid or the concentration of Na⁺ increases, it can lead to increase secreting the natriuretic peptides, reduce the re-collection of Na⁺ by the kidneys, increase sodium excretion, and cause increasing urine output and promote the water excretion.