excretion, the release of organism from the end products
of exchange, foreign substances and surplus of water, salts and
organic connections, which entered with the food or which were being
formed in the organism. As a result of exchange of substances in
the cell from it into the intercellular lymph, and then into the blood
enter carbon dioxide, some amino acids, urea, etc. with the
consumption of the surplus of salts, food substances, and also with
the disturbance of exchange in the blood rises the concentration of
neorganich. or organic substances (for example, glucose, amino acids).
Important role in the retention of the constancy of the
composition of the liquids of internal medium belongs to organs v. (homeostasis). In the process v. in
vertebrates participate the kidneys, light or the gills, the gland
of gastrointestinal tract, the skin, sweat, salt glands (nose,
rectal); in the invertebrates of protonefridii,
metanefridii, gills, etc., in the simple -
contracting vacuoles. In some
animals the products of exchange and salt are put aside in the organs
of accumulation or the cloths of the covers, which are discarded
during the moult. V. of carbon dioxide and other volatile
substances occurs through the light or the gills; water, salts,
products of nitrous exchange (ammonia, urea, urinary acid) in essence
are separated by kidneys, sodium salts in marine birds and reptiles
are separated by nose glands, in fishes - by the gills or by rectal
gland. In man by the weight of 70 kg, with the normal diet, in the twenty-four hours through the
lungs are moved away 10000-20 000 mmol" of carbon dioxide; with the urine are derived
non-volatile mineral and organic acids and only 1-2 mmol" of bicarbonates; V. of water
with the urine -1,2 l, with then 0,5 l, with the feces -0,1 l;
the general quantity of nitrogen, excreted with the urine, -11
g, with the feces -1,7 g, from then -yg. of kidney separate in a 24
hour period of 21 g of urea, 0,63 g of urinary acid, 0,56 ggippurovoy
acids, 1,05 g of creatinine, 0,78 g of ammonia. See also secretory system, water-salt exchange, respiration,
perspiration.
Lit.: ProsserL., Brown f., the
comparative physiology of animals, per.sangl., M., 1967. Yu. V. natochin.
