Macula of utricle

Macula of utricle

Infobox Anatomy
Name = PAGENAME
Latin = macula utriculi
GraySubject = 232
GrayPage = 1051


Caption = illustration of otolith organs showing detail of utricle, otoconia, endolymph, cupula, macula, hair cell filaments, and saccular nerve


Caption2 =


MapPos =
MapCaption =
Precursor =
System =
Artery =
Vein =
Nerve =
Lymph =
MeshName =
MeshNumber =
DorlandsPre = m_01
DorlandsSuf = 12509297
The portion of the utricle which is lodged in the recess forms a sort of pouch or cul-de-sac, the floor and anterior wall of which are thickened, and form the macula of utricle, which receives the utricular filaments of the acoustic nerve.

Layers

The macula consists of three layers.

The bottom layer is made of sensory hair cells which are embedded in bottom of a gelatinous layer.

On top of this layer lie calcium carbonate crystals called statoconia.

The gelatinous layer and the statoconia together are referred to as the otolith. When the head is tilted such that gravity pulls on the statoconia the gelatinous layer is pulled in the same direction also causing the sensory hairs to bend.

ignals

Depending on the direction of bending, the hair cells will either be excited or inhibited resulting in either an increase or decrease in firing frequency of the hair cells.

The macula is also sensitive to linear acceleration as the inertia possessed by the statoconia can also shift the gelatinous layer during increases and decreases in linear velocity.

External links

* http://www.neurophys.wisc.edu/h&b/textbook/chap-7.html#Obj2


Wikimedia Foundation. 2010.

Игры ⚽ Поможем написать реферат

Look at other dictionaries:

  • macula utriculi — macula utri·cu·li yu̇ trik yə .lī n MACULA ACUSTICA (b) * * * [TA] macula of utricle: a thickening in the wall of the utricle where the epithelium contains vestibular hair cells that are stimulated by linear acceleration and deceleration and… …   Medical dictionary

  • Macula (disambiguation) — Macula is a spot on the retina of the human eye, but the term may also refer to:* Macula (archaeology), a feature visible on an aerial photograph but with no identifiable function * Macula (planetary geology), a dark area on the surface of a… …   Wikipedia

  • macula acustica — macula acu·sti·ca ə küs ti kə n, pl maculae acu·sti·cae ti .sē either of two small areas of sensory hair cells in the ear that are covered with gelatinous material on which are located crystals or concretions of calcium carbonate and that are… …   Medical dictionary

  • Macula — A macula is a small spot. A macula on the skin is a small flat spot while the macula in the eye is a small spot where vision is keenest in the retina. The macula of the retina, the light sensitive layer of tissue at the back of the eye, is the… …   Medical dictionary

  • Utricle (ear) — Infobox Anatomy Name = PAGENAME Latin = utriculus GraySubject = 232 GrayPage = 1051 Caption = illustration of otolith organs showing detail of utricle, otoconia, endolymph, cupula, macula, hair cell filaments, and saccular nerve MapCaption =… …   Wikipedia

  • utricle — SYN: utriculus [TA], sacculus communis. prostatic u. [TA] a minute pouch in the prostate that opens on the summit of the seminal colliculus, the analog of the uterus and vagina in the female, being the remains of the fused caudal ends of the …   Medical dictionary

  • utricle — utriculus; n. 1) the larger of the two membranous sacs within the vestibule of the ear: it forms part of the membranous labyrinth. It is filled with fluid (endolymph) and contains a macula. This responds to gravity and relays information to the… …   The new mediacal dictionary

  • macula cribrosa superior — [TA] the perforated area on the vestibular wall through which branches of the vestibulocochlear nerve pass to the macula of the utricle and to the crista ampullaris of the anterior and lateral semicircular canals …   Medical dictionary

  • macula — n.; pl. maculae a small anatomical area that is distinguishable from the surrounding tissue. The macula lutea is the yellow spot on the retina at the back of the eye, which surrounds the greatest concentration of cones (see fovea). Maculae occur… …   The new mediacal dictionary

  • Inner ear — The cochlea and vestibule, viewed from above …   Wikipedia

Share the article and excerpts

Direct link
Do a right-click on the link above
and select “Copy Link”