"Vestibulum" and "vestibule" redirect here. For other uses, see Vestibule (disambiguation).

Vestibule of the ear
Chain of ossicles and their ligaments, seen from the front in a vertical, transverse section of the tympanum. (Vestibule visible at center right.)
Posterior Canal Superior Canal Utricle Horizontal Canal Vestibule Cochlea Saccule
Latin	vestibulum labyrinthi, vestibulum auris
Gray's	subject #232 1047

Contents 1 Definition 2 Anatomical characteristics 3 Additional images 4 External links 5 See also

[edit] Definition

The vestibule is the central part of the osseous labyrinth, and is situated medial to the tympanic cavity, behind the cochlea, and in front of the semicircular canals.

The etymology comes from the Latin vestibulum, literally an entrance hall.

[edit] Anatomical characteristics

It is somewhat ovoid in shape, but flattened transversely; it measures about 5 mm. from before backward, the same from above downward, and about 3 mm. across.

In its lateral or tympanic wall is the fenestra vestibuli, closed, in the fresh state, by the base of the stapes and annular ligament.

On its medial wall, at the forepart, is a small circular depression, the recessus sphæricus, which is perforated, at its anterior and inferior part, by several minute holes (macula cribrosa media) for the passage of filaments of the acoustic nerve to the saccule; and behind this depression is an oblique ridge, the crista vestibuli, the anterior end of which is named the pyramid of the vestibule.

This ridge bifurcates below to enclose a small depression, the fossa cochlearis, which is perforated by a number of holes for the passage of filaments of the acoustic nerve which supply the vestibular end of the ductus cochlearis.

As the hinder part of the medial wall is the orifice of the aquæductus vestibuli, which extends to the posterior surface of the petrous portion of the temporal bone.

It transmits a small vein, and contains a tubular prolongation of the membranous labyrinth, the ductus endolymphaticus, which ends in a cul-de-sac between the layers of the dura mater within the cranial cavity.

On the upper wall or roof is a transversely oval depression, the recessus ellipticus, separated from the recessus sphæricus by the crista vestibuli already mentioned.

The pyramid and adjoining part of the recessus ellipticus are perforated by a number of holes (macula cribosa superior).

The apertures in the pyramid transmit the nerves to the utricle; those in the recessus ellipticus are the nerves to the ampullæ of the superior and lateral semicircular ducts.

Behind, the five orifices of the semicircular canals can be found.

There is, in the frontal view, an elliptical opening, which communicates with the scala vestibuli of the cochlea.

[edit] Additional images

Right osseous labyrinth (lateral view).

The cochlea and vestibule (view from above).

[edit] External links

• Vestibule at eMedicine Dictionary

[edit] See also

• Inner ear

This article was originally based on an entry from a public domain edition of Gray's Anatomy. As such, some of the information contained within it may be outdated.

v • d • e Sensory system: Auditory and Vestibular systems (TA A15.3, GA 10.1029) Outer ear Pinna (Helix, Antihelix, Tragus, Antitragus, Earlobe) • Ear canal • Auricular muscles Eardrum (Umbo, Pars flaccida) Middle ear Tympanic cavity Labyrinthine wall/medial: Oval window · Round window • Secondary tympanic membrane • Prominence of facial canal • Promontory of tympanic cavity Membranous wall/lateral Mastoid wall/posterior: Mastoid cells • Aditus to mastoid antrum • Pyramidal eminence Carotid wall/anterior Tegmental wall/roof: Epitympanic recess Jugular wall/floor Ossicles Malleus (Neck of malleus, Superior ligament of malleus, Lateral ligament of malleus, Anterior ligament of malleus) · Incus (Superior ligament of incus, Posterior ligament of incus) · Stapes (Anular ligament of stapes) Muscles Stapedius · Tensor tympani Eustachian tube Bony part of pharyngotympanic tube · Cartilage of pharyngotympanic tube (Torus tubarius) Inner ear/ (membranous labyrinth, bony labyrinth) Auditory system Cochlear labyrinth General cochlea Scala vestibuli • Helicotrema • Scala tympani • Modiolus • Cochlear cupula Perilymphatic space Perilymph • Cochlear aqueduct Cochlear duct / scala media Reissner's/vestibular membrane • Basilar membrane Endolymph • Stria vascularis • Spiral ligament Organ of Corti: Stereocilia • Tectorial membrane • Sulcus spiralis (externus, internus) • Spiral limbus Vestibular system/ Vestibular labyrinth Static/translations/vestibule/endolymphatic duct: Utricle (Macula) · Saccule (Macula, Endolymphatic sac) · Kinocilium · Otolith • Vestibular aqueduct • Canalis reuniens Kinetic/rotations: Semicircular canals (Superior, Posterior, Horizontal) • Ampullary cupula • Ampullae (Crista ampullaris) ear navs: anat/pathways/physio/dev, noncongen/congen, eponymous signs, proc

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