The water-balance in the body signifies that the total intake’ of water is equal to the total ‘output’ (or excretion) of water during the 24 hours period.
The principal part of the water intake is formed by the water taken as drinks (approximately 1500 ml.) And the main part of the water output is formed by the urine (approximately 1500 ml.). Thus the kidneys play the most important role in the fluid and electrolyte balance in the body.
What is the normal electrolyte composition of the blood and what means the electrolyte balance ?
In normal health, the cations and anions of blood remain well-balanced maintaining a nearly neutral reaction (pH of 7.4).
Following is the average electrolyte composition of blood expressed in terms of milliequivalents (mEq) per liter (1) : cations (155 mEq/ 1) anions (155 mEq/1)
Sodium (Na+) 142 mEq/1 Chloride (CI ) 103 mEq/1
Potassium (K+) 5 mEq/1 Bicarbonate (HCO3) 27 mEq/1
Calcium (Ca++) 5 mEq/1 Sulphate (SOT) 1 mEq/1
Magnesium (M++) 3 mEq/1 Phosphate (HPOi~) 2 mEq/1
Other substances 22 mEq/1