MUCOUS GLANDS [glandula mucosa (PNA, JNA, BNA); synonym: mucous glands, mutsinovy glands] — the excretory glands located in a mucous membrane of appropriate authorities and cosecreting slime (mucus).
All Pages. are derivatives of an epithelium of mucous membranes (see. Glands ). Distinguish one-celled Pages., located in an epithelium of mucous membranes (endoepithelial), and multicellular, located out of an epithelium, in the thickness of a wall of bodies or beyond their limits (ekzoepitelialny). Malformations of multicellular mucous glands can lead to development of malignant and benign tumors, and obstruction of channels — to emergence of cystous educations.
One-celled Pages. are more often scattered mosaically in an epithelium of a mucous membrane of respiratory tracts, went. - kish. a path, a uterus, etc., forms continuous fields, napr, in a cover epithelium of a mucous membrane of a stomach less often. Most often occur among one-celled mucous glands scyphoid cells (see), cells, shaped are more rare than the cylinder.
Multicellular Pages. are located, as a rule, in the thickness of a wall of bodies and are presented by generally complex alveolar and tubular glands (in language, a wall of an oral cavity, a gullet, a duodenum, a trachea), more rare simple tubular glands (in a uterus, a stomach). Purely mucous multicellular glands at the person are not numerous. The mixed glands meet more often, trailer departments to-rykh contain along with mucous cells of a cell, cosecreting protein. Such glands as belong to the mixed glands submaxillary gland (see), hypoglossal gland (see). The mucous secretory cells which are a part of purely mucous and mixed glands have a similar structure. They differ from the secretory cells producing protein, larger sizes, accurate contours of cellular borders, light, foamy cytoplasm and the kernel flattened, displaced in a basal part of a cell.
At electronic microscopic examination at all one - and multicellular Pages. come to light the developed cytoplasmic reticulum and Golgi's complex. Also existence of secretory granules in cytoplasm is characteristic, to-rye are located preferential in a nadjyaderny zone and can merge, forming conglomerates. The quantity of secretory granules depends on a functional condition of a cell.
Trailer departments and output channels of difficult Pages. are surrounded with thin layers of friable fibrous connecting fabric, in to-rykh there pass blood vessels and nerves. In large glands connecting fabric forms also interlobular partitions and the capsule (a stroma of gland). As well as all glands of an organism, Page. plentifully vasku-lyarizirovana are also innervated (see. Glands ).
Function of all Pages. consists in development and removal of a mucous secret on a surface of an epithelium of a mucous membrane (see. Slime ). On a way of allocation of a secret mucous glands belong to merokrinovy, but also the apocrenic type of secretion meets, especially at stimulation (see. Secretion ). Mucous secret of all Pages. consists generally of glikozaminoglikan, preferential neutral, sialosoderzhashchy and, more rare, sulphated (see. Mutsin ). Slime, in addition to the general function of moistening of mucous membranes, has a special purpose in various bodies. So, e.g., in a trachea slime promotes adsorption of dust particles from inhaled air, in a gullet mechanically protects walls from food lumps and carries out a role of «lubricant» for simplification of their passing to a stomach, and in a uterus and fallopian (uterine) pipes slime performs also trophic function. In this regard mucous secret of various Pages. physical differs on. - to chemical properties. The chemical composition and viscosity of slime can change at dysfunction of Page. Chemical properties of a mucous secret study by means of histochemical methods (see. Mucopolysaccharides ).
Age changes of mucous glands are shown preferential in a stroma: the amount of connecting fabric and contents in it collagenic fibers increases that leads to a sklerozirovaniye of gland.
Changes in mucous glands at pathological processes. Dystrophic changes in Page., as a rule, develop for the second time, most often against the background of inflammatory processes in mucous membranes where these glands are localized (see. Bronchitis , Gastritis , Laryngitis , Rhinitis , Tracheitis , Pharyngitis , Cervicitis , Esophagitis , Enteritis , Coloenteritis ). Dystrophic changes of Page. are often combined with disturbance of their function. Proteinaceous dystrophy (see) it is characterized by muddy swelling (granular dystrophy) of mucous cells and a hyalinosis of interstitial fabric. Strengthening of a myxopoiesis and change its physical is possible. - chemical properties (see. Mucous dystrophy ). At the same time the maintenance of mucous cells considerably increases, they increase in sizes, deskvamirutsya often.
At a diabetes mellitus it is observed carbohydrate dystrophy (see), characterized by emergence of inclusions of a glycogen in cytoplasm of mucous cells of Page. Sometimes in the Village. not true slime, but muciform substances — pseudomucins collects (see. Mutsin ), to-rye can be condensed and have an appearance of a colloid (colloid dystrophy). Similar changes are observed at a colloid craw (see. Craw local ), colloid cancer (see. Cancer ).
The necrosis of mucous glands meets hl. obr. at purulent processes in mucous membranes (e.g., a necrosis of a mucous membrane of a trachea and bronchial tubes from action of OV, gangrene of a gut at obstruction of the feeding artery).
Circulatory disturbances and lymphokineses in the Village. have no independent value. They reflect only local changes at the general circulatory disturbances.
At inflammatory processes in mucous membranes destruction of Page is observed., in the stroma braiding them polymorphocellular infiltrate appears. At hron. esophagitis and hron. gastritis in trailer departments of Page. the phenomena of an atrophy of ferruterous segments are noted. In this case mucous cells get the cubic or flattened form, in their cytoplasm the quantity of secretory granules decreases. On site atrophied glands connecting fabric expands.
In some cases there is obturation of output channels of Page. slime that, in turn, leads to development of retentsionny cysts (see. Cyst ), napr, retentsionny cysts of a mucous membrane of a gullet, mucous cysts of a neck of uterus, etc.
Bibliography: Diamonds I. Century and With at - t at l about in L. S. The atlas on histology and embryology, M., 1978; Histology, under the editorship of V. G. Yeliseyev, M., 1972; The Multivolume guide to pathological anatomy, under the editorship of A. I. Strukov, t. 4, book 1, page 212, M., 1956, bibliogr.; Ham A. and Cormac D. Histology, the lane with English, t. 2, page 27, M., 1983.
Yu. K. Yelets (An., gist., embr.), G. M. Mogilevsky (patol.).