In internal hydrosphere there is an exchange between components and intensive moving of such components, as blood and interstitial a liquid. The powerful work of heart is known for everyone, every minute it banishes (4,5-5)*103 g of blood at its own weight only (2,2-3)*102 g ,and for one day this small bundle of muscles banishes more than 107 g of blood, that is tens thousand times more, than its own weight and approximately 150 times more, than the weight of the man. The huge work will be carried out by kidneys, through which 106 106 g of a liquid is banished per day. Here there is a cleaning of hydrosphere of the man from unnecessary and harmful substances, and water begins the direct way outside from here. The man consumes for the life about 7,5*107 g of water, and all the population of the planet consumes 3,6*10171017g of water. The man stand dehydration hard: if 6-8 % of a liquid from weight of a body is lost, the temperature of a body raises, the skin reddens, the palpitation and breath becomes frequent, muscular weakness and giddiness occur, the headache begins. The loss of 10 % can result irreversible changes in organism, the loss of 15-20 % is fatal at temperature of air 30 °C, and the loss of 25 % of weight of internal hydrosphere is fatal at 20-25 °C. At a similar way, but usually simplier, the internal hydrosphere of many animals works. The connection of animals with the sea is expressed also in need for salt, which gives many fibers, including fibers of hemoglobin, stability. The salt regulates many processes. Only blood contains 30 g of salt. A man needs some minimum of salt every day, without it a hard disease - uraemia begins.
