SODIUM
Extracellular fluid contains sodium for the maintenance of normal osmotic pressure and water balance. Approximately 50% of the body’s sodium is present in the extracellular fluid, 40% in bones and 10% or less in intracellular fluid. Functions
- Sodium along with chloride is major constituent in the extracelluar fluid. It is responsible to maintain osmotic pressure.
- Acid and base balance is regulated by sodium. Sodium along with calcium, magnesium and potassium are basic in reaction; but chloride with phosphate and sulphate are acidic in reaction. Thus, acid-base balance is maintained
- Sodium is concerned in the maintenance of water balance, muscle irritability contraction of muscles.
- It regulates permeability of cell membrane
- Maintenance of heart beat
- It contributes alkalinity to the gastro-intestinal secretions.
Deficiency
- Sodium deficiency occurs when the intake is poor or excessive amount is lost.
- Sodium loss through excessive sweating causes deficiency unless salt intake is not increased.
- Vomiting, severe diarrhoea, Addison’s disease is also responsible for sodium deficiency.
- There is giddiness, cramps in muscles, collapsed veins, low blood pressure, dryness of mouth, inelastic skin and oliguria.
Excess of Sodium
- Any excess of sodium in the body accumulates in the extra cellular fluids.
- The increased concentration of sodium is partially offset by an increase in these fluids.
- Sodium excess may result in oedema.
- In some the kidneys are enlarged and glomerulo nephritis may occur.
- Persons consuming 10-25 gm of salt have been found to have a high incidence of raised blood pressure.
Sources
Requirements
- Adult - 500 mg
- Children - 58 mg/day
- Infants - 2.5 mmol/day
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Last modified: Saturday, 2 June 2012, 6:29 AM