crista ampullaris


am·pul·la·ry crest

[TA] an elevation on the inner surface of the ampulla of each semicircular duct; filaments of the vestibular nerve pass through the crista to reach hair cells on its surface; the hair cells are capped by the cupula, a gelatinous protein-polysaccharide mass.
See also: neuroepithelium of ampullary crest. Synonym(s): crista ampullaris [TA], acoustic crest, transverse septum (1)

crista ampullaris

A localized thickening of the membrane lining the ampullae of the semicircular canals; it is covered with neuroepithelium containing hair cells that are stimulated by movement of the head. See also: crista

crista ampullaris

a ridge in the AMPULLA of the semicircular canals of the ear, concerned with detection of head movement. It is made up of numerous hair cells and supporting cells, the hair cells having cytoplasmic extensions embedded in a gel called the cupula. When the head moves in one direction, this creates an opposite movement in the endolymph of the canal causing displacement of the cupula which results in stimulation of the hair cells and activation of sensory neurones.