What Is an Anterior Nerve?

The vestibular nerve is a part of the auditory nerve, of which the central branch constitutes the vestibular nerve, and enters the cranial cavity through the inner ear hole with the snail nerve. After entering the pontine through the caudal end of the pontine, it terminates in the pontine and the medulla in the medulla.

The vestibular nerve is a part of the auditory nerve, of which the central branch constitutes the vestibular nerve, and enters the cranial cavity through the inner ear hole with the snail nerve. After entering the pontine through the caudal end of the pontine, it terminates in the pontine and the medulla in the medulla.

Chinese name

Vestibular nerve

Foreign name

Vestibular

Solid

Cranial nerve 8th pair

Location

The local nerve is located in the temporal bone

Features

Deliver a balanced message

Vestibular nerve overview

A small part of the fiber directly enters the cerebellum through the lower feet of the cerebellum, and ends at the pompoms and nodules. Fibers are emitted from the lateral nucleus of the vestibular nerve to form the vestibular spinal cord bundle, which terminates in the ipsilateral anterior horn cells and regulates the body's balanced movement. The other vestibular nucleus sends out fibers to participate in the medial longitudinal bundle, so that the labyrinth of the inner ear establishes a connection with the III, IV, VI cranial nerves and the upper cervical spinal column, and reflexively adjusts the position of the eyeballs and the movement of the neck. Vestibular dysfunction mainly occurs balance imbalance, dizziness, nystagmus and so on. It can be used as a temperature change test for cold and hot water perfusion of the external auditory canal, or a rotation test of a swivel chair to check the vestibular nerve.

Vestibular neuroanatomical features

In 1936, the precise location of vestibular and snail nerves in the zygomatic cranial nerve of the pontine cerebellar horn region was first reported. Subsequent studies have shown that the phrenic nerve, phrenic cranial nerve, and intermediate nerves travel in the auditory canal of the pontine cerebellar horn region. There are unique phenomena of nerve anastomosis, nerve fusion, and nerve torsion. Vestibular facial nerve anastomosis (Rasmussen's bundle) exists in the inner auditory canal near the inner auditory floor. The inferior vestibular nerve and the snail nerve also have anastomotic branches in the inner auditory canal. Similar anastomosis has not been seen between the facial nerve and the snail nerve. On the surface of the brainstem, the facial nerve is located in front of and under the vestibular cochlear nerve, and both are at the same level at the inner ear portal. At the bottom of the inner auditory canal, the facial nerve is located slightly above the superior vestibular nerve. About half of the cranial and iliac cranial nerves can be seen in the anterior inferior cerebellar artery or its branches. From the top to the bottom, there is a downward shift in the facial nerve during the walking process. From the bottom of the inner auditory canal to the brain stem, the facial nerve has a slight rotation around the longitudinal axis of the vestibular nerve. The left ear is counterclockwise and the right The ears are counterclockwise. The middle nerve emanates from the cerebellopontine angle and travels between the vestibular snail nerve and the facial nerve, and fuses with the facial nerve within the inner half of the inner auditory canal. In addition to the superior and inferior fusion of the inferior vestibular nerve with the superior vestibular nerve near the diaphragm, it also fused with the snail nerve before and after. At the bottom of the inner auditory canal, the cochlear nerve is located slightly forward of the inferior vestibular nerve, and while walking toward the center, the snail nerve and the vestibular nerve rapidly merge and rotate downward by about 90 °. From the outside to the inside, the left ear is counterclockwise and the right Is clockwise. Most of this rotation occurred in the inner auditory canal, and a small part occurred in the bridge cerebellum near the inner ear.

The cochlear vestibular fissure (the gap between the vestibular nerve and the snail nerve) exists between the snail nerve and the vestibular nerve. Due to the fusion between the snail nerve and the vestibular nerve, the rotation is shifted down by 90 °. The up and down direction of the position gradually turns to the front and back direction at the inner ear door. The number of snail nerve fibers (31,000) is more than the number of vestibular nerve fibers (18000), and the arrangement is closer, so the appearance is whiter, and the vestibular nerves are grayer. The number of nerve fibers in the cochlear and facial nerves decreased from the periphery to the brain stem, while the number of nerve fibers in the vestibular nerve increased, suggesting that during the movement, the vestibular nerves accepted part of the facial and snail nerves. Cochlear vestibular fissure can be divided into three types according to the clearly demarcated parts of the vestibular nerve and the snail nerve. Type I is located at the bottom of the internal auditory canal, type is located in the internal auditory canal, and type is located in the pontine cerebellum. About 75% of the cranial cranial nerve has a discernible cochlear vestibular fissure, which is often covered by a small artery when viewed from the back.

At the bottom of the inner auditory canal, the diaphragm and the mediastinum (Bill's Bar) separate them into relatively independent subregions, and the branches of the cranial and phrenic cranial nerves pass through these channels to the periphery. The facial nerve occupies the anterior superior, the superior vestibular nerve posterior and superior, the cochlear nerve precedes and descends, and the inferior vestibular nerve is posterior and inferior. In addition, there is a single hole behind the diaphragm, and the single hole nerve travels through it. It can also be used as a sign to open the outer boundary of the posterior wall of the inner auditory canal to prevent getting lost.