ACOUSTICAL PIPE

From Big Medical Encyclopedia

ACOUSTICAL PIPE [tuba auditiva (PNA), tuba pharyngotympanica (JNA), tuba auditiva (Eustachii) (BNA); synonym: Eustachian tube, pharyngeal and drum pipe, salpinx auditiva] — the channel connecting a nasopharynx to a drum cavity; at the person it is for the first time in detail described in 1564 by B. Evstakhy. As gained distribution in clinical practice and traditionally the term «Eustachian tube» was fixed (E. t.), it is lower and it is brought.

In phylogenesis E. t. and a drum cavity (see. Middle ear ) develop at land vertebrata as a result of transformation of a cavity of the first visceral crack. In ontogenesis E. t. and a drum cavity develop from the first pharyngeal pocket along with development of the device perceiving sound irritations. The first pharyngeal pockets grow in development lateralno while the entoderm covering them does not adjoin to an ectoderm of the first branchiate furrow on each side of a body. From a distal part of a pocket the drum cavity develops, and a proximal part is narrowed and forms E. t., keeping the message with a pharyngeal cavity.

Anatomy

E. t. — pair channel 30 — 40 mm long; diameter of its gleam is equal to 1 — 2 mm. Axis E. t. it is inclined from top to bottom and knutr, forming a corner apprx. 45 °C sagittal and apprx. 30 °C by the horizontal plane. Walls E. t. are formed partially by a bone, partially a cartilage and connecting fabric in this connection in it allocate bone and cartilaginous speak rapidly.

Bone part E. t. (pars ossea tubae auditivae) makes apprx. V3 of its length; opens on a front (sleepy) wall of a drum cavity a drum opening of an Eustachian tube (ostium tympanicum tubae auditivae). It represents the bottom of the muscular and pipe channel of a temporal bone — the semicanal of an Eustachian tube (semicanalis tubae auditivae) located in the conjunction stony p a scaly temporal bone of parts. Medially from it the sleepy channel with the internal carotid artery passing in it is located (see. Carotid arteries ).

Cartilaginous part E. t. (pars cartilaginea tubae auditivae) makes apprx. 2/3 of its lengths; it lies on an outside base of skull in a furrow at the rear edge of a big wing of a wedge-shaped bone, approaches the medial end the basis of a medial plate of an alate shoot of a wedge-shaped bone. This part E. t. it is formed by a cartilage (cartilago tubae auditivae) and a connective tissue webby plate (lamina membranacea). The cartilage has an appearance of the trench turned down and lateralno and consists of medial and lateral plates (laminae med. et lat.). Edges of a trench become isolated a webby plate. Cartilaginous part E. t. comes to an end with a pharyngeal opening (ostium pha-ryngeum tubae auditivae) located on a sidewall of a nasopharynx (see. Throat ). In the field of an opening the medial plate forms a thickening in the form of the roller (torus tubarius). The place of transition of a bone part in cartilaginous is called an isthmus of an Eustachian tube (isthmus tubae auditivae). Gleam E. t. in the field of an isthmus it is narrowed.

From walls E. t. three muscles of a soft palate originate: the muscle straining a palatine velum (m. tensor veli palatini), the muscle lifting a palatine velum (m. levator veli palatini) and a pipe and pharyngeal muscle (m. salpingopharyngeus). The muscle straining a palatine velum lies in front and lateralno and separates E. t. from an ear node, a mandibular nerve and its branches, a drum string and an average meningeal artery. A part of the fibers of this muscle beginning from a lateral plate of a cartilage E. t. and a webby plate of its wall, quite often call a dilator of an Eustachian tube. From the bottom of a cartilage E. t., near its pharyngeal opening, the trubnoglotochny muscle begins, and the muscle lifting a palatine velum originates from a medial plate of a cartilage and a webby plate. The reduction of these muscles causing shift cartilaginous and webby plates of walls E. t., influences the size of its gleam. At the deglutitory movements of a muscle open E. t., and air freely gets into a drum cavity.

At newborn (see) E. t. is shorter and wider, than at the adult, and has the form of the cylinder. Drum opening E. t. at newborns it is projected in an upper segment of a tympanic membrane, and at adults — in nizhneperedny. Such projection and form E. t. at newborns promote easier penetration of contagiums into supratympanic deepening of a drum cavity.

Arteries E. t. are branches ascending pharyngeal, average meningeal arteries and an artery of the alate channel. Veins accompany arteries and fall into a venous alate texture. Limf, vessels go in lateral retropharyngeal and' deep cervical limf. nodes. Innervation E. t. it is carried out at the expense of branches of a drum texture and a pterygopalatine node.

Histology

Mucous membrane of a wall E. t. represents continuation of a mucous membrane of a drum cavity on the one hand and nasopharynxes — with another. E. t. it is covered by the multirow ciliary epithelium containing scyphoid mucous cells. The movement of cilia of an epithelium is directed towards a nasopharynx. On a surface of an epithelium channels of mucous glands open (gll. tubariae).

Near a pharyngeal opening E. t. in a mucous membrane of a nasopharynx the accumulation of an adenoid tissue forming a pipe almond — tonsilla tubaria is concentrated (see. Almonds ).

Physiology

E. t. performs ventilating, drainage and protective functions. Ventilating function, or barofunction (see), consists in maintenance of equality of pressure on both sides tympanic membrane (see). Provided that fluctuations of a chain of acoustical stones reach the largest force that provides the best sound carrying out. Change of pressure in a drum cavity comes at the expense of a constant resorption of gases from a middle ear in fabric and owing to pressure differences in the environment. At increase in atmospheric pressure air from a nasopharynx through E. t. gets into a drum cavity, and at decrease — on the contrary, from a middle ear in a nasopharynx. Basic fiziol. the mechanism, thanks to Krom the gleam E opens. t. also air exchange on average to fish soup is carried out, the act is swallowing (see). At the time of swallowing the muscle straining a palatine velum at the same time is reduced the webby plate of cartilaginous part E is delayed. t. also its gleam reveals. On opening and closing E. t. pressure of surrounding fabrics influences. Ventilation of a middle ear is provided with reflex regulation of a gleam E. t., at the same time the receptive field of reflexes is the drum texture. At disturbance of this reflex mechanism E. t. it can be absolutely impassable for air and does not provide ventilation of a drum cavity. At disturbance of barofunction E. t. decrease in hearing and decrease in stability of a tympanic membrane is observed in relation to to a barotrauma (see). Drainage function E. t. it is directed to removal from a drum cavity of transudate or exudate. The resorption of liquid a mucous membrane of a middle ear plays a smaller role. Drainage function is provided with opening E. t. at the act of swallowing, equalization of pressure on average to fish soup, blinking of cilia of an epithelium of a mucous membrane E. t. towards a nasopharynx and the gravity of the liquid which collected in a drum cavity. Protective function E. t. it is provided with bactericidal properties of its slime emitted by mucous glands.

Methods of a research

Methods of a research come down generally to definition of passability E. t. for air. For this purpose create supertension of air in the field of a pharyngeal opening E. t. also register its passing to a drum cavity. Pressure changes the patient during the performance of test with swallowing (see. Manometriya ear ) or in Valsalva's experience (see. Valsalva experience ) or it is created artificially by ear inflation Polittser's cylinder (see. Ear inflation ). Results of researches are registered auskultativno by means of an otoscope (see. Otoskopiya ) or the ear manometer (see. Manometriya ear ). In recent years use transforming and the recorders allowing to make objective graphic registration of ventilating function of an Eustachian tube.

Pathology

Pathology of an Eustachian tube is considered continuous with pathology of a drum cavity. So, an eustachitis (see. Tubo-otitis ) it is regarded as a catarrh E. t. and drum cavity. Disturbance of drainage and protective function E. t. is the frequent reason of a purulent inflammation of a middle ear when contagiums from a nasopharynx get through E. t. in a drum cavity (see. Otitis ). Disturbance of passability E. t. is a contraindication to the work in the specialty demanding good hearing and connected with differences of atmospheric pressure (flight service, lacunar works, scuba diving, work in barooperatsionny, etc.).

Damages can be observed at catheterization E. t. (see. Ear inflation ) and bougieurage (see). In these cases manipulation should be stopped in order to avoid further traumatization of a mucous membrane and possible development of fabric emphysemas (see). Gunshot wounds E. t. though are rare, but are extremely dangerous since can often be followed by damage of a carotid artery. Treatment operational.

Foreign bodys meet extremely seldom. It can be a piece of the broken-off buzh, to-ry usually independently drops out in a cavity of a nasopharynx and only sometimes can leave in a drum cavity. In these cases carry out audit of a drum cavity and delete a foreign body.

Gaping of an Eustachian tube. The mucosal atrophy and people around E can be the cause of this pathology. t. fabrics, the tone of the muscle straining a palatine velum, etc. sometimes raised. At the same time are noted noise in an ear, autophonia (see), especially during the pronouncing concordant «m» and «N», however hearing does not decrease. At an otoskopiya the movements of a tympanic membrane, synchronous are sometimes visible to breath. In some cases gaping E. t. does not cause subjective feelings and accidentally it is found at inspection. Treatment shall be directed to elimination of the reason which caused a gaping E. t. Also massage (finger) of the pharyngeal mouth E is recommended. t. The forecast at timely treatment favorable.

Muscular noise sometimes arise at a myoclonia of muscles of a soft palate (see. Sladera syndrome , Spasms ). These noise reminding a poshchelkivaniye tips of nails are felt not only the patient, but sometimes are heard from outside. Treatment — massage (finger) of a soft palate and the pharyngeal mouth E. t. The forecast is defined by a basic disease.



Bibliography: Diseases of an ear, nose and throat, under the editorship of S. M. Kompaneshd, t. 1, p. 2, page 693, Kiev, 1937; Vulstein X. Slukhouluchshayushchy operations, the lane with it., page 31, M., 1972; Zberovskaya N. V. About differential diagnosis of changes of an acoustical pipe at patients with chronic purulent average otitis and about the forecast of a tympanoplasty depending on these changes, Vestn. otorinolar., No. 2, page 73, 1973; Ivanov G. F. Fundamentals of normal anthropotomy, t. 2, M., 1949; Preobrazhensky Yu. B. Tympanoplasty, page 30, M., 1973, bibliogr.; X e h and N and sh in and l and S. N. Urgent aspects of a kofokhirurgiya, Works of the 6th congress otolaringol. USSR, t. 2, page 123, M., 1970; Crifo S. ampere-second of i t t and-d i n i S. Studies on the tubal function by anterior rhinomanometric technique, Acta oto-rhino-laryng. belg., v. 35, p. 92, 1981; Gray’s anatomy, ed. by D. V. Davies, L., 1967; Rich A. R. Study of Eustachian tube, its related muscles, Johns Hopk. Hosp. Bull., v. 31, p. 206, 1920; S with h e i-b e A. Die Krankheiten der Ohrtrompete, Handb. Hals-, Nasen-u. Ohrenheilk., hrsg. v. A. Denker u. O. Kahler, Bd 7, T. 2, B. — Miinchen, 1926.


V. P. Gamov; E. A. Vorobyova (An., gist., embr.).

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