Water and water-salt exchange( I)

Water is the main constituent of all cells and tissues of the body and, on a par with other food substances, is an important component of nutrition.

The body of an adult person is 66-70% water. Of this amount, 3.5 liters falls on blood plasma, and 10.5 liters per lymph and extracellular fluid. The processes occurring during the metabolism can be carried out only on the condition of complete dissolution of the products entering the body and the products of metabolism. The solvent for all these elements is water. Mineral salts that create a certain osmotic pressure in the blood and tissues are dissolved in it. The colloidal state of living plasma is also provided by water. In addition, an aqueous medium is necessary for the processes occurring during digestion in the gastrointestinal tract.

Every day the body needs a certain amount of water to carry out vital functions of digesting food, removing toxins and maintaining normal body temperature. Under normal conditions, the amount of water covering the maintenance of metabolism, as well as evaporation through the skin and lungs, is only 2-2.5 liters per day. Some of the necessary water is formed in the body in the course of the oxidizing processes that take place, and a part is contained in the food. This amount is not enough, so with a drink and hot dishes in the body, you must enter up to 1.5 liters of water daily.

The physical working capacity of a person depends very much on consumption and loss of fluid. From the medical point of view, the deviation from the balance of the liquid is already 1% considered a sign of dehydration, and the loss of 7% of the total amount of fluid in the body is treated as a catastrophe!

In children 6-7 years of age, the water requirement is 60 ml per 1 kg of body weight, in schoolchildren - 50 ml. But these values ​​need to be adjusted taking into account the operating conditions, climatic and other conditions. Excess water, as well as its deficiency is equally harmful to the body. In the first case, an overload of circulatory and excretory systems is called for, and in the second case, dehydration of the body resulting in dysfunction of water metabolism.

Water is used not only in the processes that accompany metabolism, it is also necessary in order to stabilize body temperature. If necessary( intensive work, hot weather), the body is cooled by evaporation of moisture. From a medical point of view, for any warm-blooded creature, a loss of 7% of the total amount of water is a physiological catastrophe. The optimal water balance in the case of the average person( total weight 70-75 kg) under the condition of a comfortable external environment is as follows: water intake in the body is 2350 ml( drinking, food and internal processes that result in water are taken into account), and bringing togetherwith perspiration, breathing and slag - 2350 ml. .. more

Used materials:
Shilov VN, Mits'yo VP"Healthy food"