Vestibulocochlear Nerve
The structure indicated is the
vestibulocochlear nerve (cranial nerve VIII).
The vestibulocochlear nerve consists of a
vestibular branch and a
cochlear branch. The vestibular branch is responsible for
balance, and the cochlear branch is responsible for
hearing. It originates laterally in the
cerebellopontine angle and passes together with the
facial nerve into the
internal acoustic meatus of the temporal bone.
Cochlear nerve Bipolar sensory neurons in the
organ of coorti pass impulses from the hair cells of the cochlear via the peripheral axonal process to the
spiral ganglia (this is the collection of cell bodies of the cochlear nerve and it is located within the cochlear) and from these ganglia the impulse then travels via the central axonal process to the
cochlear nucleus in the brainstem. Fibres then project from the cochlear nucleus to the
inferior colliculi, the
medial geniculate bodies and then via the
internal capsule to the
auditory cortex located in the temporal lobe.
Vestibular nerve Bipolar sensory neurons convey impulse from the
vestibular hair cells located in the
utricle,
saccule and
semicircular canals to the
vestibular ganglion. The vestibular ganglion is located inside the
internal auditory meatus. From here, fibres pass either to the cerebellum or to the vestibular nuclei located in the brainstem.
Learn more about the anatomy of the
cranial nerves in this tutorial.