Formations are located on the inner wall of the tympanic cavity. Clinical anatomy of the tympanic cavity. What are the walls of the tympanic cavity formed by?

cavities

The middle ear consists of a series of interconnected air cavities: tympanic cavity(cavum tympani), auditory tube(tuba auditiva) cave entrance(aditus ad antram), caves(antrum) and related mastoid air cells(cellulae mastoidea). The middle ear communicates with the nasopharynx through the auditory tube. Under normal conditions, this is the only communication of all cavities of the middle ear with the external environment.

tympanic cavity

The tympanic cavity can be compared to an irregularly shaped cube up to 1 cm in volume. Six walls are distinguished in it: upper, lower, anterior, posterior, external and internal.

The walls of the tympanic cavity:

top wall, or the roof of the tympanic cavity (tegmen tympani) is represented by a bone plate with a thickness of 1 to 6 mm. It separates the drum-chickpea cavity from the middle cranial fossa. There are small openings in the roof through which vessels pass, carrying blood from the dura mater to the mucous membrane of the middle ear. Sometimes there are dehiscences in the upper wall. In these cases, the mucous membrane of the tympanic cavity is directly adjacent to the dura mater.

Inferior (jugular) wall or the bottom of the tympanic cavity fanichit with the jugular fossa lying under it, in which the bulb of the jugular vein is located. The lower wall can be very thin or have dehiscences through which the bulb of the vein sometimes protrudes into the tympanic cavity, this explains the possibility of injuring the bulb of the vein during surgery.

ENT diseases

front wall(tubal or carotid) is formed by a thin bone plate, outside of which is the internal carotid artery. There are two openings in the anterior wall, the upper narrow one leads to the semi-canal (semicanalis m.tensoris thympani), and the lower wide one leads to the tympanic mouth of the auditory tube (ostium tympanicum tubae auditivae). In addition, the anterior wall is permeated with thin tubules (canaliculi caroticotympanici). through which vessels and nerves pass into the tympanic cavity. In some cases, it has dehiscence.

Back wall(mastoid) 1 borders with the mastoid process. In the upper part of this wall there is a wide passage (aditus ad antrum), which connects the supratympanic space (attic) with a permanent cell of the mastoid process - a cave (antrum). Below this course there is a protrusion - a pyramidal process, from which the stirrup muscle (m.stapedius) begins. On the outer surface of the pyramidal process there is a tympanic foramen, through which the tympanic string, which departs from the facial nerve, enters the tympanic cavity. In the thickness of the posterior part of the lower wall, the descending knee of the facial nerve canal passes.

Outer (webbed) wall formed by the tympanic membrane and partly in the attic region by a bone plate that extends from the upper bone wall of the external auditory canal.

Inner (labyrinth, medial) wall is the outer wall of the labyrinth and separates it from the cavity of the middle ear. On this wall in the middle part there is an oval-shaped elevation - a cape (promotorium), formed by a protrusion of the main volute of the cochlea. Behind and upward from the promontory there is a niche of the window of the vestibule (oval window), closed by the base of the stirrup. The latter is attached to the edges of the window by means of an annular ligament. Behind and downward from the cape there is another niche, at the bottom of which there is a cochlear window (round window), leading into the cochlea and closed by the secondary tympanic membrane. Above the window of the vestibule on the inner wall of the tympanic cavity in the direction from front to back, there is a horizontal knee of the bone canal of the facial nerve (fallopian canal).

Posterior wall of the tympanic cavity(paries mastoideus) borders on the mastoid process. It is the longest wall - its length reaches 15 mm, and its height is 13-14 mm (E. B. Neishtadt). There is no wall in the upper part, it is replaced by aditus ad antrum. Under it, the wall is uneven, there is a depression to which a short process of the incus adjoins, a little lower, on the outer surface of the pyramidal protrusion, there is an opening through which the tympanic string enters the cavity, departing from the facial nerve just before it exits from the stylomastoid foramen.

self pyramidal ledge, extending from the posterior wall below the aditus, is described together with the medial wall of the tympanic cavity. The posterior wall is often demarcated from the floor of the tympanic cavity by the prominentia styloidea, a small bony protrusion formed by the fact that the apophysis of the styloid process lifts the wall of the tympanic cavity. In the depths of the posterior wall passes the canal of the facial nerve and the cells surrounding it.

Anterior wall of the tympanic cavity(paries caroticus) passes into the medial so imperceptibly that it can be considered as part of the latter. Wall height 5-9 mm, width 3-4.5 mm (E. B. Neishtadt). The upper half of the wall is occupied by the mouth of the Eustachian tube, and the lower half is represented by a thin bone plate that separates the tympanic cavity from the ascending segment of the internal carotid artery (its first bend) and the surrounding venous and sympathetic nerve plexus.

Sleepy channel the artery is surrounded by a dura mater. According to VF Vilkhonoy, in most cases the ascending part of the channel has an oblique direction, from bottom to top and back to front, less often the direction of the channel approaches the vertical. In general, the direction of the canal basically coincides with the length of the external auditory opening. The projection line of the emerging part of the carotid capal on the outer surface of the temporal bone in the region of its tympanic part runs from the base of the styloid process to the root of the zygomatic process, parallel to the length of the external auditory foramen.

Bone plate(the outer wall of the canal of the internal carotid artery) also separates the ascending segment of the artery from the bone section of the Eustachian tube, passing lateral to the carotid artery. It is practically important to know that the internal carotid artery does not pulsate in the bone canal. This is due to the fact that when entering the bone, the stack of the artery loses elastic tissue, remaining only muscular (Ramadieu). For the most part, in the anterior wall there are small pneumatic cells located radparpoly, surrounding the carotid artery drip and the bone segment of the tube.

Sometimes the carotid canal protrudes more into the tympanic cavity, as if pushing back the cape. The bone plate that separates the internal carotid artery from the mucous membrane of the tympanic cavity is penetrated by thin tubules (canaliculi carotico-tympaiiici) and often has dehiscence; these wall defects are in rare cases so significant that there is a danger of injuring the arterpus during paracentesis.

In one case, through a large perforation tympanic membrane, pulsation of the internal carotid artery was observed. With purulent otitis media (especially during an exacerbation of a chronic process), the possibility of transferring the infection through the veins that form the plexus surrounding the carotid artery to the cavernous sinus, with which these veins communicate, is not ruled out. An infection from the tympanic cavity can also pass through the carotid tubules and dehiscence to the wall of the carotid artery and eventually cause its erosion, followed by fatal bleeding.

The same bleeding may be due to caries of the anterior stack (especially TB of the middle ear), as well as accidental injury to the artery during surgery for petrositis. Bleeding only from the venous plexus in the carotid canal is possible both with pyramidal caries and during the operation to remove the Gasser node. With purulent otitis media, thrombosis of the internal carotid artery is also possible, followed by cerebral embolism.

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The middle ear consists of a series of interconnected air cavities: the tympanic cavity (cavum tympani), the auditory tube (tuba auditiva), the entrance to the cave (aditus ad antram), the cave (antrum) and the associated air cells of the mastoid process (cellulae mastoidea) . The middle ear communicates with the nasopharynx through the auditory tube. Under normal conditions, this is the only communication of all cavities of the middle ear with the external environment.

tympanic cavity

The tympanic cavity can be compared to an irregularly shaped cube up to 1 cm in volume. Six walls are distinguished in it: upper, lower, anterior, posterior, external and internal.

The walls of the tympanic cavity:

The upper wall, or roof of the tympanic cavity (tegmen tympani) is represented by a bone plate with a thickness of 1 to 6 mm. It separates the drum-chickpea cavity from the middle cranial fossa. There are small openings in the roof through which vessels pass, carrying blood from the dura mater to the mucous membrane of the middle ear. Sometimes there are dehiscences in the upper wall. In these cases, the mucous membrane of the tympanic cavity is directly adjacent to the dura mater.

The lower (jugular) wall, or the bottom of the tympanic cavity, fanichit with the jugular fossa lying under it, in which the bulb of the jugular vein is located. The lower wall can be very thin or have dehiscences through which the bulb of the vein sometimes protrudes into the tympanic cavity, this explains the possibility of injuring the bulb of the vein during surgery.

The anterior wall (tubal or carotid) is formed by a thin bone plate, outside of which is the internal carotid artery. There are two openings in the anterior wall, the upper narrow one leads to the semi-canal (semicanalis m.tensoris thympani), and the lower wide one leads to the tympanic mouth of the auditory tube (ostium tympanicum tubae auditivae). In addition, the anterior wall is permeated with thin tubules (canaliculi caroticotympanici). through which vessels and nerves pass into the tympanic cavity. In some cases, it has dehiscence.

The posterior wall (mastoid) borders with the mastoid process. In the upper part of this wall there is a wide passage (aditus ad antrum), which connects the supratympanic space (attic) with a permanent cell of the mastoid process - a cave (antrum). Below this course there is a protrusion - a pyramidal process, from which the stirrup muscle (m.stapedius) begins. On the outer surface of the pyramidal process there is a tympanic foramen, through which the tympanic string, which departs from the facial nerve, enters the tympanic cavity. In the thickness of the posterior part of the lower wall, the descending knee of the facial nerve canal passes.

The outer (membranous) wall is formed by the tympanic membrane and partly in the attic region by a bone plate that extends from the upper bone wall of the external auditory canal.

The inner (labyrinth, medial) wall is the outer wall of the labyrinth and separates it from the middle ear cavity. On this wall in the middle part there is an oval-shaped elevation - a cape (promotorium), formed by a protrusion of the main volute of the cochlea. Behind and upward from the promontory there is a niche of the window of the vestibule (oval window), closed by the base of the stirrup. The latter is attached to the edges of the window by means of an annular ligament. Behind and downward from the cape there is another niche, at the bottom of which there is a cochlear window (round window), leading into the cochlea and closed by the secondary tympanic membrane. Above the window of the vestibule on the inner wall of the tympanic cavity in the direction from front to back, there is a horizontal knee of the bone canal of the facial nerve (fallopian canal).

Tympanic cavity, cavitas tympanica (Fig.,,; see Fig.,,), is a slit-like cavity in the thickness of the base of the pyramid of the temporal bone. It is lined with a mucous membrane that covers six of its walls and continues behind into the mucous membrane of the cells of the mastoid process of the temporal bone, and in front - into the mucous membrane of the auditory tube.

Outdoor membranous wall, paries membranaceus, the tympanic cavity for a greater extent is formed by the inner surface of the tympanic membrane, above which the upper wall of the bone part of the ear canal takes part in the formation of this wall.

Internal labyrinthine wall, paries labyrinthicus, the tympanic cavity is at the same time the outer wall of the vestibule of the inner ear.

In the upper part of this wall there is a small depression - dimple of vestibule window, fossula fenestrae vestibuli, which has vestibule window, fenestra vestibuli(see Fig. , ), - an oval hole covered with the base of the stirrup.

In front of the dimple of the window of the vestibule, on the inner wall, the septum of the musculo-tubal canal ends in the form cochlear process, processus cochleariformis.

Below the window of the vestibule is a rounded elevation - cape, promontorium, on the surface of which there is a vertical cape furrow, sulcus promontorii.

Below and behind the cape is a funnel-shaped snail window dimple, fossula fenestrae cochleae where is the round window snail, fenestra cochleae(see fig.).

The dimple of the cochlear window is limited from above and behind by a bone roller - cape stand, subiculum promontorii.

Snail window closed secondary tympanic membrane, membrana tympani secundaria(see fig.). It is attached to the rough edge of this hole - scallop window snail, crista fenestrae cochleae.

Above the snail's window and behind the promontory is a small depression called tympanic sinus, sinus tympani.

Upper tire wall, paries tegmentalis, the tympanic cavity is formed by the bone substance of the corresponding section of the petrous part of the temporal bone, which received the name due to this roofs of the tympanic cavity, tegmen tympani. In this place, the tympanic cavity forms an upward epitympanic recess, recessus epitympanicus, and its deepest section is called dome part, pars cupularis.

The bottom wall (bottom) of the tympanic cavity is called jugular wall, paries jugularis, due to the fact that the bone substance of this wall takes part in the formation of the jugular fossa. This wall is uneven and contains air , as well as the opening of the tympanic tubule. The jugular wall bears a small styloid protrusion, prominentia styloidea, which is the base of the styloid process.

Posterior mastoid wall, paries mastoideus, the tympanic cavity has a hole - cave entrance, aditus ad antrum. He leads to mastoid cave, antrum mastoideum, which in turn communicates with mastoid cells, cellulae mastoideae.

On the medial wall of the entrance there is an elevation - protrusion of the lateral semicircular canal, prominentia canalis semicircularis lateralis, below it there is an arcuate from front to back and downwards protrusion of the facial canal, prominentia canalis facialis.

In the upper medial part of this wall is pyramidal eminence, eminentia pyramidalis, with embedded in its thickness stirrup muscle, m. stapedius.

On the surface of the pyramidal eminence there is a small depression - incus fossa, fossa incudis, which includes a short leg of the anvil.

Slightly below the fossa of the incus, on the anterior surface of the pyramidal eminence, under the protrusion of the facial nerve is located posterior sinus, sinus posterior, and below, above the styloid protrusion, opens tympanic aperture of the tubule of the drum string, apertura tympanica canaliculi chordae tympani.

Front carotid wall, paries caroticus, the tympanic cavity bears tympanic cells, cellulae tympanicae. Its lower section is formed by the bone substance of the posterior wall of the canal of the internal carotid artery, above which is located tympanic opening of the auditory tube, ostium tympanicum tubae auditivae.

Clinicians conventionally divide the tympanic cavity into three sections: lower, middle and upper.

To lower section tympanic cavity ( hypotympanum) carry part of it between the lower wall of the tympanic cavity and a horizontal plane drawn through the lower edge of the tympanic membrane.

middle department tympanic cavity ( mesotympanum) occupies most of the tympanic cavity and corresponds to that part of it, which is limited by two horizontal planes drawn through the lower and upper edges of the tympanic membrane.

Upper section tympanic cavity ( epitympanum) is located between the upper border of the middle section and the roof of the tympanic cavity.

76. Clinical anatomy of the tympanic cavity.

tympanic cavity - the space enclosed between the eardrum and the labyrinth. In shape, the tympanic cavity resembles an irregular tetrahedral prism, with the largest upper-lower size and the smallest between the outer and inner walls. Six walls are distinguished in the tympanic cavity: external and internal; upper and lower; anterior and posterior.

Outer (lateral) wall represented by the tympanic membrane, which separates the tympanic cavity from the external auditory canal. Above the tympanic membrane, the plate of the upper wall of the external auditory canal participates in the formation of the lateral wall, to the lower edge of which (incisura Rivini) the tympanic membrane is attached.

In accordance with the structural features of the lateral wall, the tympanic cavity is conditionally divided into three sections: upper, middle and lower.

Upper - epitympanic space, attic, or epitympanum - located above the upper edge of the stretched part of the tympanic membrane. Its lateral wall is the bone plate of the upper wall of the external auditory canal and pars flaccida eardrum. In the supratympanic space, the articulation of the malleus with the anvil is placed, which divides it into external and internal sections. In the lower part of the outer part of the attic, between pars flaccida the tympanic membrane and the neck of the malleus is the upper mucosal pocket, or Prussian's space. This narrow space, as well as the anterior and posterior pockets of the tympanic membrane (Treltsch's pockets) located downward and outward from the Prussian space, require mandatory revision during surgery for chronic epitympanitis in order to avoid recurrence.

Middle part of the tympanic cavity - mesotympanum - the largest in size, corresponds to the projection pars tensa eardrum.

Lower (hypotympanum)- depression below the level of attachment of the tympanic membrane.

Medial (internal) the wall of the tympanic cavity separates the middle and inner ear. In the central section of this wall there is a protrusion - a cape, or promontorium, formed by the lateral wall of the main whorl of the cochlea. The tympanic plexus is located on the surface of the promontorium. . The tympanic (or Jacobson's) nerve is involved in the formation of the tympanic plexus , nn. trigeminus, facialis, as well as sympathetic fibers from plexus caroticus internus.

Behind and above the cape is vestibule window niche, in shape resembling an oval, elongated in the anteroposterior direction. Entrance window closed stirrup base, attached to the edges of the window with annular ligament. In the region of the posterior lower edge of the cape, there is snail window niche, protracted secondary tympanic membrane. The niche of the cochlear window faces the posterior wall of the tympanic cavity and is partially covered by a projection of the posteroinferior clivus of the promontorium.

Topography facial nerve . Joining with n. statoacousticus and n. intermediate into the internal auditory meatus, the facial nerve passes along its bottom, in the labyrinth it is located between the vestibule and the cochlea. In the labyrinth region, the secretory portion of the facial nerve departs large stony nerve, innervates the lacrimal gland, as well as the mucous glands of the nasal cavity. Before entering the tympanic cavity, above the upper edge of the vestibule window, there is geniculate ganglion, in which the taste sensory fibers of the intermediate nerve are interrupted. The transition of the labyrinth to the tympanic region is denoted as the first knee of the facial nerve. The facial nerve, reaching the protrusion of the horizontal semicircular canal on the inner wall, at the level pyramidal eminence changes its direction to vertical (second knee) passes through the stylomastoid canal and through the foramen of the same name extends to the base of the skull. In the immediate vicinity of the pyramidal eminence, the facial nerve gives a branch to stirrup muscle, here it departs from the trunk of the facial nerve drum string. It passes between the malleus and anvil through the entire tympanic cavity above the eardrum and exits through fissura petrotympanica, giving taste fibers to the anterior 2/3 of the tongue on its side, secretory fibers to the salivary gland, and fibers to the vascular plexuses. front walltympanic cavity- tubal or sleepy . The upper half of this wall is occupied by two openings, the larger of which is the tympanic mouth of the auditory tube. , over which the semi-canal of the muscle that stretches the eardrum opens . In the lower section, the anterior wall is formed by a thin bone plate that separates the trunk of the internal carotid artery, which passes in the canal of the same name.

Posterior wall of the tympanic cavity - mastoid . In its upper section there is a wide course (aditus ad antrum) through which the epitympanic space communicates with cave- a permanent cell of the mastoid process. Below the entrance to the cave, at the level of the lower edge of the vestibule window, on the back wall of the cavity is located pyramidal elevation, containing m. stepedius, the tendon of which protrudes from the top of this eminence and goes to the head of the stirrup. Outside of the pyramidal eminence is a small hole from which the drum string emerges.

Top wall- the roof of the tympanic cavity. This is a bony plate that separates the tympanic cavity from the middle cranial fossa. Sometimes there are dehiscences in this plate, due to which the dura mater of the middle cranial fossa is in direct contact with the mucous membrane of the tympanic cavity.

Inferior wall of the tympanic cavity - jugular - borders on the bulb of the jugular vein lying under it . The bottom of the cavity is located 2.5-3 mm below the edge of the tympanic membrane. The more the bulb of the jugular vein protrudes into the tympanic cavity, the more convex the bottom has and the thinner it is.

The mucous membrane of the tympanic cavity is a continuation of the mucous membrane of the nasopharynx and is represented by a single-layer squamous and transitional ciliated epithelium with a few goblet cells.

In the tympanic cavity are three auditory ossicles and two intra-ear muscles. The chain of auditory ossicles are interconnected joints:

* hammer (malleus); * anvil (incus); * stirrup (stapes).

The handle of the malleus is woven into the fibrous layer of the tympanic membrane, the base of the stirrup is fixed in the niche of the vestibule window. The main array of auditory ossicles - the head and neck of the malleus, the body of the anvil - are located in the epitympanic space. In the malleus, the handle, neck and head, as well as the anterior and lateral processes are distinguished. The anvil consists of a body, short and long processes. A short branch is located at the entrance to the cave. Through a long process, the anvil is articulated with the head of the stirrup. The stirrup has a base, two legs, a neck and a head. The auditory ossicles are interconnected by means of joints that ensure their mobility; there are a number of ligaments that support the entire ossicular chain.

Two ear muscles carry out the movements of the auditory ossicles, providing accommodation and protective functions. The tendon of the muscle that strains the eardrum is attached to the neck of the malleus. m. tensor tympani. This muscle begins in the bony semi-canal above the tympanic mouth of the auditory tube. Its tendon is initially directed from front to back, then bends at a right angle through the cochlear protrusion, crosses the tympanic cavity in the lateral direction and attaches to the malleus. M. tensor tympani innervated by the mandibular branch of the trigeminal nerve.

stirrup muscle is located in the bone sheath of the pyramidal eminence, from the opening of which the muscle tendon emerges in the region of the apex, in the form of a short trunk it goes anteriorly and is attached to the head of the stirrup. Innervated by a branch of the facial nerve n. stepedius.

77. Anatomy of the membranous labyrinth

membranous labyrinth It is a closed system of cavities and canals, the shape of which basically repeats the bone labyrinth. The space between the membranous and bony labyrinth is filled with perilymph. The cavities of the membranous labyrinth are filled with endolymph. Perilymph and endolymph represent the humoral system of the ear labyrinth and are functionally closely related. Perilymph in its ionic composition resembles cerebrospinal fluid and blood plasma, endolymph - intracellular fluid.

It is believed that endolymph is produced by the vascular streak and reabsorbed in the endolymphatic sac. Excessive production of endolymph by the vascular streak and a violation of its absorption can lead to an increase in intralabyrinthine pressure.

From an anatomical and functional point of view, two receptor apparatuses are distinguished in the inner ear:

Auditory, located in the membranous cochlea (ductus cochlearis);

Vestibular, in vestibular sacs (sacculus and utriculus) and in three ampullae of the membranous semicircular canals.

membranous snail, or cochlear duct located in the cochlea between the scala vestibuli and the scala tympani. On a transverse section, the cochlear duct has a triangular shape: it is formed by the vestibular, tympanic and outer walls. The upper wall faces the staircase of the vestibule and is formed by a thin, squamous epithelial cell vestibular (Reissner) membrane.

The floor of the cochlear duct is formed by a basilar membrane that separates it from the scala tympani. The edge of the bone spiral plate through the basilar membrane is connected to the opposite wall of the bone cochlea, where it is located inside the cochlear duct spiral bond, the upper part of which, rich in blood vessels, is called vascular strip. The basilar membrane has an extensive network of capillary blood vessels and is a formation consisting of transverse elastic fibers, the length and thickness of which increases in the direction from the main curl to the top. On the basilar membrane, located spirally along the entire cochlear duct, lies organ of corti- peripheral receptor of the auditory analyzer.

spiral organ consists of neuroepithelial inner and outer hair cells, supporting and nourishing cells (Deiters, Hensen, Claudius), outer and inner pillar cells that form the arches of Corti. Inward from the internal pillar cells is a number of internal hair cells; outside of the outer pillar cells are the outer hair cells. Hair cells are synaptically connected to peripheral nerve fibers originating from the bipolar cells of the spiral ganglion. The supporting cells of the organ of Corti perform supporting and trophic functions. Between the cells of the organ of Corti there are intraepithelial spaces filled with a fluid called cortylymph.

Above the hair cells of the organ of Corti is located cover membrane, which, like the basilar membrane, departs from the edge of the bone spiral plate and hangs over the basilar membrane, since its outer edge is free. The integumentary membrane consists of protofibrils, having a longitudinal and radial direction, hairs of neuroepithelial outer hair cells are woven into it. In the organ of Corti, only one terminal nerve fiber approaches each sensitive hair cell, which does not give branches to neighboring cells; therefore, degeneration of the nerve fiber leads to the death of the corresponding cell.

membranous semicircular canals are located in the bone canals, repeat their configuration, but smaller than them in diameter, with the exception of the ampullar sections, which almost completely fill the bone ampullae. Connective tissue strands, in which the supply vessels pass, membranous canals are suspended from the endosteum of the bone walls. The inner surface of the canal is lined with endothelium, in the ampullae of each of the semicircular canals are ampullary receptors, representing a small circular protrusion - crest, on which the supporting and sensitive receptor cells are located, which are peripheral receptors of the vestibular nerve. Among the receptor hair cells, thinner and shorter immobile hairs are distinguished - stereocilia, the number of which reaches 50-100 on each sensitive cell, and one long and thick mobile hair - kinocilium, located on the periphery of the apical surface of the cell. The movement of endolymph during angular accelerations towards the ampulla or the smooth knee of the semicircular canal leads to irritation of neuroepithelial cells.

On the eve of the labyrinth there are two membranous sacs- elliptical and spherical (utriculus et sacculus), in the cavities of which are located otolith receptors. AT utriculus semicircular canals open sacculus connects with the cochlear duct by the reunium duct. Accordingly, sacs receptors are called macula utriculi and macula sacculi and represent small elevations on the inner surface of both sacs lined with neuroepithelium. This receptor apparatus also consists of supporting and sensitive cells. The hairs of sensitive cells, intertwining with their ends, form a network that is immersed in a jelly-like mass containing a large number of calcium carbonate crystals in the form of octahedrons. The hairs of sensitive cells, together with otoliths and a jelly-like mass, form otolithic membrane. Among hairs of sensitive cells, as well as in ampullar receptors, kinocilia and stereocilia are distinguished. The pressure of otoliths on the hairs of sensitive cells, as well as the displacement of hairs during rectilinear accelerations, is the moment of transformation of mechanical energy into electrical energy in neuroepithelial hair cells. The elliptical and spherical sacs are interconnected by a thin tubule , which has a branch - endolymphatic duct . Passing in the aqueduct of the vestibule, the endolymphatic duct enters the posterior surface of the pyramid and there it blindly ends with the endolymphatic sac. , which is an extension formed by a duplication of the dura mater.

Thus, vestibular sensory cells are located in five receptor areas: one in each ampulla of the three semicircular canals and one in two sacs of the vestibule of each ear. In the nerve receptors of the vestibule and semicircular canals, not one (as in the cochlea), but several nerve fibers are suitable for each sensitive cell, so the death of one of these fibers does not entail the death of the cell.

Blood supply to the inner ear through the labyrinthine artery , which is a branch of the basilar artery or its branches from the anterior inferior cerebellar artery. In the internal auditory meatus, the labyrinthine artery divides into three branches: the vestibular , vestibulocochlear and snail .

Features of the blood supply of the labyrinth consist in the fact that the branches of the labyrinthine artery do not have anastomoses with the vascular system of the middle ear, the Reissner membrane is devoid of capillaries, and in the region of the ampullar and otolithic receptors, the subepithelial capillary network is in direct contact with neuroepithelial cells.

Venous outflow From the inner ear it goes along three paths: the veins of the aqueduct of the cochlea, the veins of the aqueduct of the vestibule and the veins of the internal auditory canal.