Wednesday, February 2, 2011

Vestibulocochlear Nerve (CN VIII)

The vestibulocochlear nerve, also known as cranial nerve VIII (CN VIII), is composed of sensory fibers which carry two types of sensory information to the brain: balance and hearing. It is the 8th of the twelve cranial nerves. The vestibulocochlear nerve is made up of bipolar neuron axons and splits into two branches: 1) the vestibular nerve, which carryies sensory information about balance; 2) the cochlear nerve, carrying information about hearing. The CN VIII enters the brain stem at the junction of the pons and medulla, lateral to the facial nerve. The auditory component of the eighth nerve terminates in a sensory nucleus called the cochlear nucleus, which is located at the junction of the pons and medulla. The vestibular part of the CN VIII ends in the vestibular nuclear complex located in the floor of the fourth ventricle.