HYPODERMIC FATTY TISSUE [tela subcutanea (PNA, JNA, BNA); synonym: hypodermic basis, hypodermic fabric, hypoderma] — the friable connecting fabric with fatty deposits connecting skin with more deeply the located fabrics. It forms hypodermic kletchatochny spaces (see), in to-rykh there are trailer departments of sweat glands, vessels, limf, nodes, cutaneous nerves.
Item. to. develops from mezenkhimny rudiments, so-called primary fatty bodies. They are put to 3V2 to month of embryonic development in skin of a cheek and a sole, and by 4,5 months — in skin of other parts of a body of a fruit.
Anatomy and histology
Basis of the Item. to. make the connective tissue fibrous tyazh formed by bunches of collagenic fibers with impurity of elastic fibers (see. Connecting fabric ), originating in a mesh layer skin (see) and going to a superficial fascia, edges are delimited by the Item. to. from the subject fabrics (own fascia, a periosteum, sinews). On thickness distinguish fibrous tyazh of the 1, 2 and 3 order. Between tyazha of the 1st order there are thinner tyazh of the 2nd and 3rd order. The cells limited to fibrous tyazha of various order entirely are filled with segments fatty tissue (see), forming fatty deposits (panniculus adiposus). Structure of the Item. to. defines its mechanical characteristics — elasticity and durability on stretching. In the places subject to pressure (a palm, a sole, the lower third of buttocks), the thick fibrous tyazh penetrating hypodermic cellulose perpendicular to a body surface and oorazuyushchy retinaculums of skin (retinacula cutis) which densely fix skin to the subject fabrics prevail, limiting its mobility. Similarly skin of a pilar part of the head connects to a tendinous helmet. Where skin is mobile, fibrous tyazh are located slantwise or parallel to a body surface, forming laminated structures.
Fatty deposits in hypodermic cellulose of a fruit up to 7 months are insignificant, but quickly accrue by the end of the pre-natal period. In an organism of the adult they average apprx. 80% of all mass of the Item. to. (the percent strongly varies depending on age of t of a floor and features of a constitution). Fatty tissue is absent only under skin a century, a penis, a scrotum, a clitoris and small sexual: lips. Its contents in a hypodermic basis of a forehead, nose, outside ear, lips is insignificant. On the flexion surfaces of extremities the content of fatty tissue is more, than on extensive. The biggest fatty deposits are formed on a stomach, buttocks, at women also on a breast. There is a close correlation between thickness of the Item. to. in various segments of extremities and on a trunk. Ratio of thickness of the Item. to. at the man and the woman averages 1: 1,89; its general weight at the adult man reaches 7,5 kg, the woman has 13 kg (respectively 14 and 24% of body weight). At senile age the lump of fatty tissue under skin decreases and its distribution becomes disproportionate.
In nek-ry parts of a body in the Item. to. muscles are located, at reduction to-rykh skin in these parts gathers in folds. Cross-striped muscles are in hypodermic cellulose of the person [mimic muscles (face muscles, T.) ] and necks (a hypodermic muscle of a neck), unstriated muscles — in a hypodermic basis of external genitals (especially in a dartos of a scrotum), an anus, a nipple and a peripapillary circle of a mammary gland.
Item. to. it is rich with blood vessels. Arteries, getting into it from the subject fabrics, form dense network on border with a derma. From here their branches go in fibrous tyazha and are divided into the capillaries surrounding each fatty segment. In the Item. to. veniplexes are formed, in to-rykh large saphenas form. Limf, vessels of the Item. to. originate in a deep limf, network of skin and go to regional limf, nodes. Nerves form a shirokopetlisty texture in a deep layer of the Item. to. Sensitive nerve terminations are presented in hypodermic fabric by lamellar little bodies — Fater's little bodies — Pa-repair (see. Nerve terminations ).
Functions of the Item. to. are diverse. External shapes of a body, turgor and mobility of skin, expressiveness of skin furrows and folds in many respects depend on it. Item. to. represents power depot of an organism and actively participates in lipometabolism (see); it plays a role of the thermoinsulator of a body, and the brown fat which is available for fruits and newborns is body of heat production (see. Fatty tissue ). Thanks to the elasticity of the Item. to. performs function of the shock-absorber of external mechanical influences.
Pathological changes in the Item. to. can be connected with disturbances of a lipometabolism. At endogenous and exogenous forms of obesity (see) in the Item. to. the quantity of fatty segments at the expense of a hyperplasia of lipocytes and increase in fat in their cytoplasm (a hypertrophy of lipocytes) increases. At the same time there is a formation of new capillaries, and in lipoblasts destructive changes quite often are found. Decrease in amount of fat in cytoplasm of lipoblasts is noted at exhaustion. At the same time kernels of cells hold central position, their volume often increases.
Mucoid and fibrinoid swelling of connecting fabric of the Item. to. (see. Mucous dystrophy , Fibrinoid transformation ) occurs at collagenic diseases (see). Amyloidosis (see) meets seldom. Amyloid can be found in a wall of vessels, is more rare around follicles of hair, grease and sweat glands. Calcification (see) it is possible on small sites, in a zone of dystrophic changes of fabric. E.g., at sclerodermas (see) salts of calcium are postponed in the form of grains, glybok or layered educations with perifocal inflammatory reaction.
Necrosis of the Item. to. develops at local disturbances of blood circulation, bruises, an injection of some pharmaceuticals (e.g., solutions of magnesium sulfate, calcium chloride, etc.) and chemical in-in (e.g., gasoline), at burns, freezing injuries etc. (see. Fatty necroses , Necrosis ). In fatty segments there is zymolysis of neutral fat to formation of fatty acids and soaps which irritate surrounding fabrics, causing perifocal productive inflammatory reaction with existence of huge multinucleate cells (see. Lipogranuloma ).
Arterial hyperemia of the Item. to. arises at inflammatory processes in skin and the Item more often. to. also has generally local character. At the general venous stagnation in the Item. to. the picture of hypostasis develops. As a result of disturbance of a lymph drainage in the Item. to. there are sclerous changes. Hemorrhages in the Item. to. have diffuse character and are followed by bystry absorption of decomposition products of blood.
Nonspecific inflammatory processes most often have exudative character — serous, purulent, fibrinous. A specific place is held by Pfeyffer's syndrome — Weber — Krischena (the recurrent not suppurating spontaneous panniculitis) which is characterized by focal destruction of fatty tissue with development of inflammatory reaction (see. Panniculitis ). Morfol, picture of specific inflammatory diseases of the Item. to. does not differ from that in other bodies and fabrics (see. Syphilis , Tuberculosis extra pulmonary ).
Patol. the processes caused in the Item. to. fungi, are quite various that depends on properties of fungi and reaction of an organism to them. At gistol, a research in the Item. to. the changes inherent hron, to inflammatory processes, with the features caused by a type of the activator are found (see. Mycoses ).
Atrophy of the Item. to. arises at various forms cachexias (see). Item. to. gets ocherous-yellow coloring that is connected with concentration of a pigment of a lipochrome, fatty tissue becomes impregnated with edematous liquid. Hypertrophy of the Item. to. most often happens vicarious, napr, at an atrophy of muscles of extremities.
Atrophy, hypotrophy and hypertrophy of the Item. to. come down to reduction or increase in fatty deposits. They can arise owing to inborn malformations of the Item. to., but are often caused by many patol, processes. So, atrophy of the Item. to. arises at anorexia, starvation, hypovitaminoses, the progressing lipoidodistrofiya, the heavy course of traumatic exhaustion, it is purulent - resorptive fever, sepsis, malignant tumors, etc. Hypertrophy of the Item. to. it is observed, as a rule, at disturbances of a lipometabolism owing to functional changes of a hypophysis, thyroid and gonads, at an adiposagenital syndrome, obesity, long hormonal therapy, especially by Prednisolonum. Overdevelopment of fatty tissue can be diffusion or focal (see. Lipomatoz ); fatty deposits are especially considerable in mental area, mammary glands, an abdominal wall, on buttocks. Lipomatoz with development of the dense round painful centers in the Item. to. on the course of nervous trunks has the neuroendocrinal nature (see. Derkuma disease ).
Treatment of an atrophy, hypo - and hypertrophies of the Item. to. it has to be directed to elimination of the reason which caused them. In nek-ry cases (in particular, on hips and a stomach) make for removal of excess fatty deposits plastic surgeries (see), and sometimes at the general obesity — operation with switching off of a considerable part of a small bowel (see. Obesity ).
At the closed injury of the Item. to. hemorrhages (see) which are usually shown by decolourization of skin are observed (from lilovokrasny to flavovirent); are sometimes formed hematomas (see). A peculiar form of the closed injury of the Item. to. traumatic amotio of skin together with a hypodermic basis from the subject dense fabrics is (a fascia, an aponeurosis), edges it is observed at the tangential direction of the operating force (transmission, drawing on asphalt at transport injuries, etc.). More often it happens on an outer surface of hips, in the field of a sacrum, a waist. Insignificant hemorrhage in these cases quickly stops, and the formed cavity slowly is filled with a lymph, being shown by clinically fluctuating swelling, contents a cut move at change of position of the patient. The diagnosis is not difficult if to remember a possibility of such injury. At conservative treatment absorption of a lymph goes very slowly; suppurations with extensive purulent are frequent zatekam (see). At open damages to the Item. to., through to-ruyu there passes the wound channel, along with clots bone fragments, scraps of material of clothes of the victim and other foreign bodys can contain (see. Wounds, wounds ). Poisonous foreign bodys (in particular, graphite of an indelible pencil) and some chemical substances (kerosene, turpentine, etc.) which were included in the Item. to., serve as the reason of rough deep inflammatory and necrotic process. Wound of the Item. to. is followed an indelible pencil on condition of the fragments which remained in it by plentiful lymphorrhea (see), the edge does not stop before their removal.
Treatment of the closed injuries of the Item. to. at an aseptic current generally conservative. In the presence of a big hematoma, and also in case of suppuration or calcification of a hematoma operational treatment (a puncture, a section, excision) is shown,
At traumatic amotio of skin repeated punctures (sometimes with an injection of antibiotics) with the subsequent imposing of a compressing bandage are necessary; at suppuration make a section with counteropenings (see). At open, especially fire, wounds of L. to. primary is necessary surgical treatment of wounds (see). The poisonous foreign bodys and chemicals which were included in the Item. to., are subject to urgent operational removal with excision of surrounding soft tissues.
Deep (the III—IV degrees) thermal burns cause a necrosis of the Item. to. (see. Burns ).
The most frequent type of pathology of the Item. to. its inflammation is — panniculitis (see). Causative agents of the Acute nonspecific infection (staphylococcus, a streptococcus, colibacillus, proteas, etc.) can get into the Item. to. through skin (at microtraumas) or in the presence furuncle (see) or anthrax (see) way of transition from a bag of a hair and sebaceous glands and to cause formation of abscess (see) or phlegmons (see). Phlegmon often arises at to an ugly face (see), especially at phlegmonous and gangrenous its forms. The hematogenous and lymphogenous ways of infection which are noted more often at are possible sepsis (see). The expressed changes in the Item. to. are observed at hron, inflammatory processes — pyodermas (see), to a lipogranuloma (see), etc. The disturbances of a lymphokinesis caused by inflammatory processes in the Item. to. — a lymphostasis (see), lymphangiectasias (see) — play an essential role in a pathogeny and a wedge, a picture of elephantiasis (see). At nek-ry specific processes (an actinomycosis, tuberculosis) in the Item. to. the fistular courses are formed (see. Fistulas ) or natechnik (see).
Treatment of inflammatory processes of the Item. to. complex: an operative measure according to indications, antibacterial therapy and other conservative actions.
From parasitic diseases, at to-rykh the activator it is localized in the Item. to. (preferential lower extremities), meets more often dracunculosis (see), quite often complicated by a consecutive bacterial infection with development of abscess, phlegmon, trophic ulcer and allergic manifestations (hypostasis of an extremity, a synovitis, arthritis, etc.).
Benign tumors of the Item. to. — a lipoma and a fibrolipoma (see. Lipoma ) — sometimes reach the big sizes; they rather easily leave in the operational way. From malignant tumors of the Item. to. seldom meets liposarcoma (see). Timely treatment it (an operative measure and chemotherapy) can give a favorable outcome. Peculiar tumor of the Item. to. represents hibernoma (see), proceeding it is good-quality or zlokachestvenno. Quite often in the Item. to. metastasises (including implantation) various malignant tumors can develop.
Bibliography: Voyno-Yasenetsky V. F. Sketches of purulent surgery, JI., 1956; Davydovsky I. V. General pathology of the person, page 89, M., 1969; Kalantayevskaya K. A. Morphology and physiology of skin of the person, page 19, Kiev, 1972; Kovanov V. V. and Anikina T. I. Surgical anatomy of fastion and kletchatochny spaces of the person, page 5, M., 1967; The Multivolume guide to pathological anatomy, under the editorship of A. I. Strukov, t. 1, page 231, M., 1963; The Multivolume guide to surgery, under the editorship of B. V. Petrovsky, t. 2, M., 1964; Sorokin A. P. General patterns of a structure of the basic device of the person, page 33, M., 1973; With t r at to about in A. I. and With e r about in V. V. Pathological anatomy, page 37, M., 1979; V. I Pods. Purulent surgery, M., 1967; it, General surgery, M., 1978; The Person, Medicobiological data, the lane with English, page 57, M., 1977. See also bibliogr, to St. Abscess, Derkuma disease, Fatty tissue, Lipometabolism, Anthrax, Lipoma, Elephantiasis, etc.
M. A. Korendyasev; G. M. Mogilevsky (stalemate. An.), V. S. Speransky (An.).