SALIVATION — secretory activity of sialadens. Pages provide three couples of big sialadens (parotid, submaxillary and hypoglossal), and also the small glands located in an oral cavity (lip, buccal, palatal, lingual and gingival). The page plays an important role in ensuring processing and absorption of foodstuff, maintenance of a homeostasis, implementation of secretory, endocrine and protective functions.
Small sialadens cosecrete constantly, moistening a mucous membrane of an oral cavity. Page of large sialadens (see. Parotid gland , Submaxillary gland , Hypoglossal gland ) has the reflex nature: begins at influence of conditioned food excitators (a look, a flavor of food, verbal signals) and amplifies under the influence of unconditional irritations of receptors of an oral cavity (see. Roth, oral cavity ) both the food, and rejected substances. Besides, at the person S. of parotid and hypoglossal glands promotes implementation of speech function.
S.'s regulation is carried out by the nerve centers located in myelencephalon (see), hypothalamus (see) and to a cerebral cortex (see). The centers C. of a myelencephalon consist of two symmetrically located groups of nervous cells in kernels of a reticular formation — nuclei salivatorii superiores et inferiores (see. Reticular formation ). The centers C. of a cerebral cortex are located in the field of a silviyevy furrow, upper frontal and orbital crinkles (see. Furrows and crinkles of a cerebral cortex ).
Studying of the mechanism C. was begun in 19 century. According to R. Geydengayn's theory which is put forward by it in 1868, release of water and salts at S. happens under the influence of secretory nerves, and S. of organic matters — at excitement trophic. Then it was revealed that parasimpatichesk denervated gland shows the increased secretory activity, to-ruyu K. Bernard called paralytic secretion. In the subsequent it was shown that in the first 1 — 3 day after denervation secretion is caused by emission of acetylcholine. Then emission of a mediator stops, sensitivity of ferruterous cells to biologically active agents increases, and under the influence of catecholamines of blood there is a paralytic secretion. Denervation perverts also the answer of ferruterous cells on various chemical agents. So, in innervated glands atropine blocks S., and after a postganglionic denervatspa strengthens it (a so-called salivary atropinic paradox).
For the purpose of S.'s studying in hron. an experiment at animals I. P. Pavlov was. the operation consisting in imposing of a fistula of a salivary channel is offered. For this purpose the papilla of a channel of parotid or submaxillary gland is hemmed to an outer surface of a cheek. At the person S. study by means of Leshli's capsule — Yushchenko — Krasnogorsk, containing internal and outside cameras: internal is put to an output channel and strengthened a sucker to the outside camera. Place a flowmeter in the internal camera. Especially the microelectrode-nye of a research is a lot of for understanding of the mechanism C. of a distance modern (see. Microelectrode method of a research ). With their help it was established that serous and mucous cells have various polarization of apical and basal membranes, and their excitement is connected not with depolarization, and with so-called exciting hyperpolarization. It is shown also that ferruterous cells and sialadens answer stimulation of both sympathetic, and parasympathetic nerves (with stage of latency duration apprx. 0,4 sec.) that, apparently, confirms complexity of the neyrogumoral-ny mechanism of regulation of Page.
Normal at the person about 2 l of saliva a day are allocated. Owing to strengthening of both salivary reflexes, and spontaneous S. the amount of saliva can increase several times (hypersalivation). Hypersalivation is observed at the persons having Parkinson's disease, epidemic encephalitis, disturbance of cerebral circulation, stomatitis, toxicosis of pregnant women, helminthosis, an epileptiform neuralgia. At the same time the strengthened hypersalivation (ptyalism) can be such that the patient is not able to swallow saliva. Decrease in secretion of saliva (i.e. a hypoptyalism) is followed by a xerostomia — xerostomia (see). The hypoptyalism (a giposialiya, a sialopeniya) and an asialia (i.e. extreme degree of a hypoptyalism) are symptoms as general diseases (septic states, pneumonia, diabetes, malignant anemia, sypny and a typhoid, etc.), and pathologies actually of sialadens, their inflammations (see. Sialadenitis ), obstruction of output channels (see. Sialolithiasis ).
Bibliography: Babayevo A. G. and Sh at - N and to about in and E. A. Struktura, function and adaptive growth of sialadens, M., 1979; Babkin B. P. Secretory mechanism of digestive glands, JI., I960; B and r and and sh R. D. Regulation of secretion of enzymes of sialadens, Usp. fiziol. sciences, t. And, La 1, page 73, 1980; At t to and N of V I. Mechanisms of formation of electrolytic structure of secrets of sialadens, Usp. sovr. biol., t. 78, century 3(6), page 4, ‘14, 1974, bibliogr.; it, Biophysical bases of secretion of an organic macromolecular product cells of sialadens, Usp. fiziol. sciences, t. 7, No. 1, page 94, 1976, bibliogr.; Pavlov And, Item. Complete works, t. 2, book 2, page 11, M. — L., 1951; With and z and m of a JI. Diseases of sialadens, the lane from Czeches., Prague, 1971; Physiology of the autonomic nervous system, under the editorship of O. G. Baklavadzhyan, etc., JI., 1981; Physiology of digestion, under the editorship of A. V. Solovyov, etc., L., 1974.
V. I. Gutkin.