QS Study

The vestibulocochlear nerve is the eighth paired cranial nerve. It consists of two anatomically and functionally separate parts: the cochlear nerve, distributed to the hearing organ, and the vestibular nerve, distributed to the organ of balance. This nerve is conscientious for the sense of hearing.

Synonym: 8th Cranial nerve, Auditory Nerve, Acoustic Nerve, in the human ear.

Origin, course & termination –

Vestibular nerve: The nerve fibers of it are the central process of nerve cells present in the vestibular ganglion. They enter the anterior surface of the brainstem in a groove between the lower border of pons & upper part of the medulla oblongata. The superior division of the vestibular nerve carries sensory fibers from the hair cells of the anterior and lateral semicircular canals and utricle. It is located in the poster superior quadrant

When they enter the vestibular nuclear complex, the fibers are divided into short ascending & long descending fibers; a small number of fibers pass directly to the cerebellum through the inferior cerebellar peduncle by passing the vestibular neuclei.

Vestibulocochlear Nerve 1

Fig: Vestibulocochlear Nerve

Cochlear nerve: The fibers of it are the central process of the nerve cells located in the spiral ganglion of the cochlea. They enter the anterior surface of the brainstem at the lower border of the pons. It relays with the first order sensory cells in the spiral ganglion, which is in the base of the spiral lamina.

On entering the pons, the nerve fibers are divided into two branches, One branch enters the posterior cochlear nucleus & another branch enters the anterior cochlear nucleus.

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