Crista ampullaris

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Crista ampullaris
Identifiers
Dorlands
/Elsevier
c_62/12266540
TA A15.3.03.088
FMA 77714
Anatomical terminology
Semicircular canal: ampulla at medium magnification with a hemotoxylin & eosin stain

The crista ampullaris is the sensory organ of rotation. They are found in the ampullae of each of the semicircular canals of the inner ear, meaning that there are 3 pairs in total. The function of the crista ampullaris is to sense angular acceleration and deceleration.

Background[edit]

The inner ear comprises three specialized regions of the membranous labyrinth: the vestibular sacs – the utricle and saccule, and the semicircular canals, which are the vestibular organs, as well as the cochlear duct, which is involved in the special sense of hearing.

The semicircular canals are filled with endolymph, and also contain an inner membranous sleeve that form the semicircular canals. The canals also contain the crista ampullaris. The receptor cells located in the semicircular ducts are innervated by the eighth cranial nerve, the vestibulocochlear nerve (specifically the vestibular portion).

The crista ampullaris itself is a cone-shaped structure, covered in receptor cells called "hair cells". Covering the crista ampullaris is a gelatinous mass called the cupula. Upon angular acceleration (rotation), the endolymph within the semicircular duct deflects the cupula against the hair cells of the crista ampullaris. The hair cells respond by stimulating neurons that innervate them.

References[edit]

Ovalle, William (2008). Netter's Essential Histology. Philadelphia, PA USA: Saunders Elsevier. p. 448. ISBN 978-1-929007-86-8. 

External links[edit]