The physiological process that maintains the balance of water and mineral salts in the body is called osmoregulation.
Most of the water is excreted from the body through urine. When the amount of water in the body decreases by 20%, the physical activity is disturbed. If you take more liquids, the amount of water in the body increases.
1. Maintaining water balance: If excess water is lost through excess sweat and urine, water deficiency occurs in the body. It increases blood density. The news of this change in blood reaches the hypothalamus and the osmoreceptors of the hypothalamus are stimulated. Therefore, antidiuretic hormone (ADH) is produced from the posterior pituitary gland in the process of neurosecretion. ADH increases renal tubular permeability. The renal tubule reabsorbs large amounts of water from the glomerular filtrate and returns it to the blood. It produces less urine and is excreted from the body. This work continues until the water balance in the body.
Again, when the amount of water in the body increases, the blood becomes more fluid. The news of this change in blood reaches the hypothalamus. As a result, the production of antidiuretic hormone (ADH) by the posterior pituitary gland stops or decreases. This causes the renal tubules to become impervious. Renal tubular reabsorption of water from the glomerular filtrate ceases (or is greatly reduced). As a result, more urine is produced and excreted from the body. Urine volume can increase up to 16 ml per minute. This process continues until the water balance in the body.
2. Maintenance of sodium ion balance: Na+ ion concentration in human body is 142 mmol/L in extracellular fluid and 10 mmol/L in intracellular fluid. In a healthy body this concentration is always constant. During intake of food and drink more Na+ ions enter the body than required. Excess Na+ ions are removed from the body through urine, feces and sweat. As a result, sodium ion balance is maintained in the body.
3. Maintenance of potassium ion balance: The concentration of K+ ions in the human body is 4 mmol/L in the extracellular fluid and 160 mmol/L in the intracellular fluid. In a healthy body this concentration is always liquid. When consuming different types of fruits, more K+ ions enter the body than required. Excess K+ ions are removed from the body through urine and feces. As a result, the balance of potassium ions in the body is maintained.