Membranous labyrinth

Last revised by Francis Deng on 22 Mar 2022

The membranous labyrinth or endolymphatic labyrinth is the part of the inner ear housed in the osseous labyrinth. It comprises 3 distinct, but joined, sensory sacs and ducts supplied by the vestibulocochlear nerve (CN VIII):

As the membranous labyrinth is smaller than the osseous labyrinth, the two are separated by perilymph, which does not communicate with the endolymph contained in the membranous labyrinth.

The inferior vestibular branch of the vestibulocochlear nerve (CN VIII) supplies the saccule. The inferior vestibular branch also gives off the singular nerve which courses through foramen singulare to supply the posterior semicircular duct.

The superior vestibular branch of the CN VIII supplies the utricle, superior (anterior) and lateral (horizontal) semicircular ducts.

The cochlear branch of CN VIII supplies the cochlear duct.

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