Nervus vestibularis

The vestibular nerve is one of the two branches of the vestibulocochlear nerve (the cochlear nerve being the other).

In humans the vestibular nerve transmits sensory information transmitted by vestibular hair cells located in the two otolith organs (the utricle and the saccule) and the three semicircular canals via the vestibular ganglion of Scarpa.

Information from the otolith organs reflects gravity and linear accelerations of the head.

Information from the semicircular canals reflects rotational movement of the head.

Both are necessary for the sensation of body position and gaze stability in relation to a moving environment. Axons of the vestibular nerve synapse in the vestibular nucleus are found on the lateral floor and wall of the fourth ventricle in the pons and medulla. It arises from bipolar cells in the vestibular ganglion which is situated in the upper part of the outer end of the internal auditory meatus. Structure The peripheral fibers divide into three branches (some sources list two): the superior branch passes through the foramina in the area vestibularis superior and ends in the utricle and in the osseous ampullae of the superior and lateral semicircular ducts; the fibers of the inferior branch traverse the foramina in the area vestibularis inferior and end in the saccule; the posterior branch runs through the foramen singulare and supplies the ampulla of the posterior semicircular duct.