vestibular apparatus

(anatomy) The anatomical structures concerned with the vestibular portion of the eighth cranial nerve; includes the saccule, utricle, semicircular canals, vestibular nerve, and vestibular nuclei of the ear.

The equilibrium receptors of the inner ear, consisting of the utricle, saccule, and semicircular canals, that are sensitive to the orientation of the head with respect to gravity, to the rotation of the head, and to balance. Impulses from the vestibular apparatus are conducted along vestibular nerve fibres to the vestibular complex in the brain stem and cerebellum. The complex initiates visual and motor responses that help maintain balance.