Our body contains approximately 1.8 g of sodium per kg of our weight.
Functions of Sodium
- Sodium is the principal electrolyte in the extracellular fluid which maintains normal osmotic pressure and water balance. It serves as a base in extracellular fluid.
- It contributes alkalinity to the gastro-intestinal secretions.
- Along with other ions, it maintains the normal irritability of nerve cells and muscle contractions.
- It regulates cell permeability.
- It maintains electrolyte differences between intracellular and extra-cellular fluid compartments.
Deficiency of Sodium
- Sodium depletion occurs in athletes and persons engaged in heavy labour. they lose significant amounts of sodium in sweat. Fluid must be taken liberally.
- A hormonal deficiency of ACTH in Addison's disease leads to large losses of sodium so that the patient hungers for sodium.
- Sodium depletion also occurs during continuous vomiting and diarrhoea.
- muscle cramps
- in severe depletion there is circulatory failure.