FATTY TISSUE

From Big Medical Encyclopedia

FATTY TISSUE (textus adiposus) — a kind of connecting fabric. Consists of lipocytes (lipoblasts), each of which contains a drop of fat. Cytoplasm scanty, fine-grained, has an appearance of a narrow rim; the kernel is located on the periphery of a cell. Between lipocytes collagenic, reticular and elastic fibers, circulatory capillaries, nerve fibrils, histiocytes, fibroblasts, lymphoid elements, labrocytes (mast cells) are located. In one places of friable not properly executed connecting fabric lipocytes can be located one by one among other cells' and intercellular substance, in others — form the bigger or smaller size of accumulation or the whole segments. The fatty drop of a lipocyte consists of neutral fat with impurity fat to - t and cholesterol. Fat contains pigments — the lipochromes giving it yellowish coloring. V Zh. t. the quantity of a glycogen is found a nek-swarm.

Fig. 7. Microdrug of skin of a sole of a fruit of 16 weeks: initial stages of accumulation of fat — pink inclusions (coloring by Sudan of III and hematoxylin; X 400).
Fig. 8. Microdrug of skin of a cheek of a fruit of 16 weeks: all lipoblasts contain fat — is painted in orange color (coloring by Sudan of III; X 70).

. t. develops from accumulations of mezenkhimny cells. By 3rd month of an antenatal life in cytoplasm there are small fatty droplets (tsvetn. fig. 7 and 8), which, quickly merging, form one drop which is pushing aside a kernel to the periphery. At electronic and microscopic studying of lipocytes almost total absence in them a granular cytoplasmatic reticulum and poor development of a lamellar complex (Golgi's complex) is established. It is connected with functional specialization of lipocytes which accumulate lipidic inclusions and almost do not synthesize a squirrel at all. V Zh. t. not only collect, but also fatty substances are produced, there is a synthesis of fats from carbohydrates, and also splitting of fatty substances to release of carbohydrates. On high exchange activity. t. specifies a large number of the dehydrogenases which are contained in it dehydrogenating fat to - you (see. Lipometabolism ).

Accumulation and mobilization of lipids in. t., directly connected with a metabolism in an organism, are possible at rich vascularization of fatty tissue when each lipocyte is in direct or close connection with circulatory capillaries. The last are final departments of the artery entering each fatty segment.

Ability is known. t. to fill in an organism of space, formed owing to a decrease of other fabric (vakatny obesity). . t. participates in water exchange. Release of water at an expenditure of fat matters at starvation and active physical. to the work which is followed by the strengthened sweating. Restriction of ingress of water leads to reduction of an adiposity. t., being a bad conductor of heat, plays a role of a heat insulator.

In some areas of a body, in particular on soles of feet, between internals. t., being in relationship with fibrous connecting fabric, acts as the shock-absorbing structure protecting bodies from mechanical influences.

At the adult of average weight with a normal metabolism total quantity. t. reaches 6 — 10 kg. Volume. t. depending on the level of exchange processes changes; similar fluctuations are made in considerable limits that is not peculiar to other body tissues. These changes are connected with jump of quantitative content of various inclusions in a cell and growth. t. At sharply expressed exhaustion of an organism lipocytes in many body parts completely disappear. At the same time. t. accepts a structure of initial friable not properly executed fibrous connecting fabric.

Topography of deposits. t. in an organism in usual conditions of life activity has nek-ry pattern. A considerable part it is presented by a hypodermic fatty layer. Other part is in structure of serous covers, hl. obr. in big and an omentulum, between bodies of chest and belly cavities, and also on the course of blood vessels and nerves.

For identification of fatty inclusions on gistol, drugs there are special methods of coloring: osmium tetroxide, sharlakhy red, Sudan-III, etc.

In addition to usual — so-called white. t., there is brown. t. It occurs in a significant amount at the animals falling into hibernatation. Feature borax Zh. t. the fact that at starvation of an organism it loses fatty inclusions after usual is. t. At the person brown. t. find in the embryonal period, after the birth it turns into usual. t., sometimes remaining in the form of rudimentary educations. Fabric richly in a vaskulyarizirovan. In addition to neutral fats, in borax Zh. t. it is a lot of fat to - t, cholesterol and phospholipids. Consider that brown. t. the depot of complex fats and vitamins is, there are data on communication by borax Zh. t. with adrenal glands, and also about its role as temperature regulator at newborns (see. Lipometabolism ).

Pathology

Overdevelopment. t. can be as the general (obesity), and local (lipomatoza). Exogenous factors — plentiful food with a large amount of carbohydrates, systematic alcohol intake can be the cause of obesity. Endogenous forms of obesity are connected with various hormonal disturbances (see. Obesity ). For lipomatoza (see) focal overdevelopment is characteristic. t. in the form of lipomas, sometimes multiple. Manifestation of a lipomatoz is Derkum's disease — development in hypodermic cellulose in the course of nervous trunks of the painful nodes or diffusion growths having a structure of a lipoma (see. Derkuma disease ).

Reduction. t. in volume it is noted at starvation, some hron, diseases, malignant tumors, regional lipodystrophies, napr, at the progressing lipodystrophy (Barraker's disease — Simmons).

Specific inflammatory processes in. t. proceed as well as in other fabrics. Nonspecific inflammations have a number of idiosyncrasies. E.g., a purulent inflammation in. t. differs in a rapid current and purulent fusion (see. Phlegmon ). At hron, inflammations and necroses of various origin in. t. (see. Fatty necroses ) develop panniculites (see) and lipogranulomas (see), sometimes with calcification

. t. can be a source high-quality (lipomas, fibrolipomas) and malignant (liposarcoma) tumors. Brown. t. also can be a source of benign and malignant tumors — hibernomas (see).



Bibliography: De Robertis E., Novinsky V. and Saes F. Cytobiology, the lane with English, M., 1973; 3 and in and r-z and A. A N. Chosen works, t. 4, M. — L., 1953; And about with t of X. Physiology of a cell, the lane with English, M., 1975; Nyyuskholm E. and Start To. Regulation of metabolism, the lane with English, M., 1 977; Polikar A. and Sh. A Bo. Submicroscopic structures of cells and fabrics it is normal also of pathology, the lane with fr., L., 1962; Maximow A. Bindegewebe und blutbildente Gewebe, Handb, mikroskop. Anat. d. Menschen, hrsg. v. W. Mollendorff, Bd 2, T. 1, S. 232, B., 1927.

S. I. Shchelkunov.

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