Water exchange

Water exchange is a set of processes of absorption of water introduced into the body by drinking and food, its distribution in the body, water formation in the oxidation of fats, carbohydrates and proteins in the tissues and water excretion by the kidneys, lungs, skin, and intestines. Water exchange is a constituent part of the General metabolism of the body.
The total water content in the adult organism is 65-70% ( embryo reaches 97%), while water is available in free and bound state. Free water is easily moves from cells in the extracellular space plasma of blood, lymph and back; bound water firmly held mainly proteins. In a healthy adult human body retains water balance (balance), i.e. the quantity of water consumed and produced in the body, equal to the number of allocated water. The total amount consumed by drinking and food water is 2000-2500 ml, including drinking - 1200-1500 ml per day. The allocation of water occurs mainly through the kidneys (50-60%), the rest is through the skin, lungs and intestines. Water exchange is regulated by the Central nervous system and hormones. The dysfunction of regulatory systems can cause severe damage to the water balance and water balance, such as swelling with diabetes, nephritis and other
Water exchange in children. In children water exchange has a number of features associated with greater intensity of metabolic processes, lack of concentration ability of the kidneys, the loss of water due to the imperceptible perspiration (the excretion of water through the skin and respiratory organs) and imperfection of neurohumoral regulation of digestion and excretion of water from the body.
The child is born in a state of physiological overhydration (water content is 75 - 80% of body weight). In the next day at the newborn marked negative water balance, caused a great loss of water through the lungs kidneys (emphasis isotonic urine), with meconium. However, the total water content continues to be high. The intensity of water exchange in children, especially in early childhood, is associated with a high relative body surface. The younger the child, the more the relative surface of the body and the greater the loss of water. So, if the adult in water exchange takes part 1/7 part of the extracellular fluid, the infant - half. Minor content of bound water in the extracellular fluid due to the weak development of connective tissue creates conditions gidrolabilna (see Gidrolabilna).
In the first six months after birth, the water content is gradually decreasing and in the future is within 65% regardless of age and sex. In the period of puberty in boys, there is a slightly higher content of water in the body, than girls. The decrease in the total water content in the growth of the child takes place only owing to the extracellular fluid. The amount of water inside the cells in relation to body weight is virtually unchanged. The influence of age on water exchange is particularly intense effect on the first year of life. Cm. also the Metabolism and energy.