The cochlea (plural: cochleae) is part of the inner ear osseous labyrinth found in the petrous temporal bone. It contains the cochlear duct, part of the membranous labyrinth which senses hearing.

Gross anatomy

The cochlea is a shell-shaped spiral that turns between two-and-a-half and two-and-three-quarters times around the modiolus (a central column of porous bone).

The spiral of the cochlea is separated by the osseous spiral lamina and consists of the scala tympani (lower portion), scala media and scala vestibuli (upper portion).

The scala tympani and scala vestibuli are filled with perilymph and the scala media by endolymph.

The organ of Corti, a strip of sensory epithelium located in the scala media, lines the spiral of the cochlea.

The round window is an opening (covering by a membrane) in the middle ear that communicates with the cochlea and enables movement of cochlear lymph.


Related pathology