Vestibulocochlear nerve (Latin)

The n. vestibulocochlearis (CN VIII) arises from the brainstem (truncus encephali) at the junctio pontomedullaris /angulus pontocerebellaris. It exits the cranium via the meatus acusticus internus of the os temporale, where it divides into the n. vestibularis and n. cochlearis. The n. vestibularis contains the axons of neurons whose cell bodies are found in the ganglion vestibulare, found at the lateral end/fundus of the meatus acusticus internus. The ganglion vestibulare consists of a pars superior/inferior, from which the r. superior and r. inferior of n. vestibularis arise and proceed to innervate the vestibular apparatus (utriclus, sacculus and ductus semicirculares). The n. ampullaris anterior, n. ampullaris lateralis and n. utricularis arise from the r. superior, while the n. ampullaris posterior and n. saccularis are given off from the r. inferior. These nerves collect the information related to motion and position of the head and transmit it to the nuclei vestibulares (ncll. vestibularis superior, inferior, medialis et lateralis) in the lower pons/upper medulla oblongata in order to maintain balance and equilibrium. The n. cochlearis contains the axons of neurons whose cell bodies are located in the ganglion cochleare/spirale, that lies in the canalis spiralis secundaria (spiral canal of modiolus) of the cochlea. Peripheral processes of these neurons send terminal endings to receptors in the organum spirale (of Corti), that collect auditory information and transmit it via the n. cochlearis to the nuclei cochleares (ncl. cochlearis anterior and posterior) in the truncus encephali, and ultimately to the primary auditory cortex of the lobus temporalis.