DEPOSITION

From Big Medical Encyclopedia

DEPOSITION (Latin deponere to lodge) — process of storage of various substances in an organism with their subsequent use. Sometimes understand process of accumulation in fabrics of various substances, harmful to an organism as D. (toxins, radioactive materials, etc.) that is not absolutely reasonable. Each substance has the specifics of D., however there are elements D., general for all substances: inclusion of substance in depot, storage and its change in depot, escaping of depot, Neyrogumoralnaya regulation of process of D. as system reaction of a complete organism. Depending on the place of storage and type of depot distinguish external and internal D. K to the first refer finding of reserve air in lungs, food in a stomach, bile in a gall bladder. By internal D. consider adjournment in fabrics of fats, carbohydrates, mineral salts, hormones, vitamins, mediators in synoptic bubbles, oxygen, and also deposition of blood (see. Blood depot ).

Value D. for a human body is defined by the fact that it is one of factors of creation of dynamic constancy of internal environment, a cut, according to K. Bernard, provides free life in various conditions of the environment (see. Homeostasis ). In D.'s implementation the important role is carried out by blood circulation. Advance of salts and water from blood in intercellular space depends on a gradient of falling of blood pressure in a circulatory capillary, speed of a blood-groove in it, on hydrostatic pressure in intercellular space, speed of the movement of a lymph and difference of oncotic pressure in blood and fabric. Transition of water-salt liquid and other substances from an interintercellular lymph in cells is made in various ways. Passive advance of substance is defined gradient (see) concentration of substance out of and in a cell, existence of a difference of potentials between an inner and outer surface of a membrane, and also a flow of the solvent getting through a membrane and taking with itself molecules of solute. Active transfer of substance through a membrane is connected with power consumption, a source a cut usually ATP is. Transferable substance comes to a cell with a molecule carrier (protein, a lipid). Nek-rym to cells svoystven way of capture of substance in the way phagocytosis (see) or pinocytic (see); these processes sometimes combine endocytosis (exocytosis) in one concept.

Processes of neurohumoral regulation of each type of D. are a component of system reaction of a complete organism. So, e.g., transition of carbohydrates to fat and its accumulation in a fat depo amplifies insulin, and an exit of fat from depot and increase it are stimulated in a liver with glucocorticoids. The lipolysis is promoted by a glucagon, lipocainum and catecholamines. D.'s disturbance is connected with pathology of regulation of exchange processes (e.g., obesity, a pituitary cachexia, diabetes).

Is studied by various methods: marked atoms, scanning of bodies, elektropletizmografichesk, etc.


Bibliography: Barkroft J. The main lines of architecture of physiological functions, the lane with English, page 126, M. — L., 1937; And OST of X. Physiology of a cell, the lane with English, page 38, 720, M., 1975; Human physiology, under the editorship of E. B. Babsky, M., 1972.

N. V. Danilov.

Яндекс.Метрика