FLAVOURING ANALYZER

From Big Medical Encyclopedia

FLAVOURING ANALYZER - the morpho-physiological system providing perception and the analysis of the chemical substances coming to an oral cavity.

Flavoring kidneys are found in a human fruit aged apprx. 3 months. V. of ampere-second of the first days of life of the child begins to function: there are positive reactions to sweet and subacidic solutions and negative — on bitter and salty. Development of kidneys goes up to 45 years, then their number begins to decrease, especially flavoring kidneys of zhelobovidny nipples of language considerably atrophy. Reduction of number of flavoring kidneys leads to decrease in flavoring sensitivity.

Century and. is available for various types of animals. In an evolutionary row there is a complication of the organization B. and, So, at V.'s insects and. form 4 — 5 nervous cells which are contained in touch hairs (activity of one of them is enough for formation of the difficult behavioural act). Fishes have flavoring kidneys, and they are capable to analyze various tastes of substances of an organic origin (extract of an earthworm etc.). Century and. amphibians allows to distinguish all tastes of food and water. At

V.'s birds and. it is developed insufficiently though flavoring kidneys are described at birds of different types. Elektrofiziol, by method it is established that at pigeons and chickens only some substances excite flavoring receptors.

Century and. consists of peripheral, conduction and central departments.

Peripheral department it is presented by the receptor cells which are in structure of flavoring kidneys and carrying out reception of taste (see). They are located hl. obr. on a surface language (see).

Conduction department of V. and. it is formed of the fibers departing from receptor cells which gather in the nervous stipitates passing in structure of a drum string (chorda tympani) and glossopharyngeal nerve (n. glossopharyngeus). The fibers of a drum string representing peripheral shoots of cells of a cranked node (gangl. geniculi), innervate fungoid nipples on a front surface of language. The central shoots of these cells pass in structure of an intermediate nerve (n. intermedius), single path (tractus solitarius) in a solitary kernel of a single path of a myelencephalon (nucleus tractus solitarii). Fibers of a glossopharyngeal nerve innervate zhelobovidny, leaflike nipples of a back third of language, a soft palate and represent peripheral shoots of cells of the lower node of a glossopharyngeal nerve [gangl. inferius (PNA), gangl. petrosum (BNA)] which central shoots as a part of a single path also come to a solitary kernel. Elektrofiziol, by researches on animals it is established that the main flavoring bulbar zone is a rostral part of this kernel. In it are close located and partially block each other of a zone of a projection of gustatory nerves. At irritation of flavoring receptors activation of neurons is observed also in amygdaloid kernels and Staderini's (nucleus intercalatus) kernel.

Scheme of conduction paths of somatic n. trigeminus (V) fibers, flavoring n. facialis (VII) and n. glossopharyngeus (IX) fibers: and — a cerebral cortex; — a visual hillock; in — the bridge (varoliyev the bridge) and a mesencephalon; — a myelencephalon; 1 — capsula interna; 2 — a somatosensory zone of bark; 3 — front operkulo-insulyarny area of bark; 4 — nucleus inferior posteromedialis thalami; 5 — lemniscus medialis; 6 — nucleus tractus solitarii; 7 — nucleus tractus spinalis nervi trigemini

Bulbar zone B. and. it is characterized by a certain hemotopichesky organization that is expressed in separate representation of the receptors sensitive to sweet and bitter. From a kernel of a single path the second sensitive neuron begins, the axon to-rogo forms decussation, being in structure of a medial loop (lemniscus medialis), and terminates in ventral and medial kernels of a thalamus (fig). Electrophysiologically it is established that a median part of a ventral kernel reacts to flavoring, and lateral departments — on mechanical and thermal irritations of language.

The fibers of the third neuron transferring flavoring information to bark (operculum temporale gyri parahippocampalis) originate from kernels of a thalamus. At monkeys cortical projection of V. and. is located in two areas: in representation of language in a somatosensory zone of bark and in a lateral furrow on front operkulo-insulyarny area of bark. Gustatory nerves have own, partly blocking zones of a projection in these two sites of bark.

Neurons of various zones B. and. are characterized by wide sensitivity to chemical substances. Neurons of thalamic kernels are influenced stronger by a complex incentive (e.g., quinine + sugar). Cortical neurons perceive information not only on taste of food, but also on its temperature, degree of rigidity.

The flavoring feeling results from integrative activity of all levels B. and. The simplest form of the flavoring analysis, napr, assessment of degree of sweet of various substances, occurs already at the level of receptors. More irregular shape of the flavoring analysis, napr, assessment of concentration of components in mix of substances, is carried out on bulbar and more high levels. The thinnest forms of the analysis of flavoring properties of separate substances and mixes are carried out with participation of cortical department of the analyzer.

V.'s activity and. it is closely connected with operation of the digestive device. On the one hand, V. and. reflex «starts» department of saliva and a gastric juice; on the other hand, level of activity of V. and. depends on a degree of admission food went. - kish. path. So, sensitivity of flavoring receptors, maximum on an empty stomach, after meal (or its introductions to a stomach through a fistula) considerably decreases. An essential role is played by V. and. in the preferable choice of this or that foodstuff. At deprivation of food of taste and a smell, and also denervation of an oral cavity, destruction of thalamic kernels or cortical department of V. and. the flavoring analysis is completely violated.

V.'s activity and. at the person it is investigated psikhofiziol, methods — by means of the feelings arising at effect of flavoring solution on certain sites of language or separate nipples at animals — by means of electrophysiologic registration of electric activity of separate kernels of V. and.

In medical practice it must be kept in mind a possibility of dysfunction of V. and. at beam influence that can be caused by direct injury of flavoring receptors (in case of radiation of an oral cavity) or mediated (at total radiation or radiation of separate parts of a body). The most sharply expressed fluctuations of threshold sizes of irritations were noted at irritation by bitter and sweet solutions.

Dysfunction of V. and. it is revealed at gamma and x-ray radiation of maxillofacial area. Against the background of development of changes of a mucous membrane of an oral cavity with the phenomena of an atrophy, the increased keratinization of an epithelium and emergence of erosion in language the progressing reduction of quantity of the functioning fungoid nipples and a perversion of flavoring perceptions is noted.

The changes noted at local and total radiation of people can be also caused by disturbances of a functional condition of c. in the N of page called by radiation.

Dysfunctions of V. and. are established at acute and hron, a form radial illness (see). At treatment of beam injuries of a mucous membrane of an oral cavity and normalization of the functional condition of c changed owing to radiation. and. the page is possible recovery of function B. and.

See also Analyzers .


Bibliography: Abuladze K. S. Studying of reflex activity of salivary and lacrimal glands, M., 1953, bibliogr.; Guskov and A. K. and Baysogolov G. D. Radial illness of the person, page 174, M., 1971; Kassil V. G. Taste, in book: Fiziol, touch systems, under the editorship of G. V. Gershuni, the p. 2, page 562, L., 1972, bibliogr.; Kononova E. P. Conduction paths, Mnogotomn, the management on nevrol., under the editorship of N. I. Grashchenkov, t. 1, book 2, page 166, M., 1957, bibliogr.; Borg G. and. the lake of Neural and psychophysical responses to gustatory stimuli, in book: The skin senses, ed. by D. R. Kenshalo, p. 368, Springfield, 1967; Pfaffmann C. Physiological and behavioral processes of the sense of taste, Giba found. Symp., p. 31, L., 1969.

A. I. Esakov; L. B. Koznova (I am glad.)

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