Cochlear nucleus

The cochlear nuclei ( " screw cores " ) are two core areas ( nuclei ) in the brain stem, serving the first switching of the auditory pathway. The afferents run in the cochlear nerve (part of the eighth cranial nerve ), the auditory information organ of Corti of the inner ear leads to the brain. There are two screw cores that extend to the floor of the fourth ventricle of the medulla oblongata to the pons:

• Cochlear nucleus anterior (front screw core )
• Cochlear nucleus posterior (rear screw core )

Cochlear nucleus anterior

Most efferent fibers of the anterior screw core cross to the other side of the brain ( contralateral) and shape it on the underside of the brain visible from the outside transverse structure, the trapezoid body. Subsequently, most axons run in the lateral lemniscus to the respective lower hill ( inferior colliculus ) of the quadrigeminal plate ( quadrigeminal ). Part of the efferent fibers pulls the medial geniculate body and from there via the Hörstrahlung to the auditory cortex.

A portion of the fibers extends from the trapezoid body to the eye muscle nuclei (nucleus nervi abducentis, nucleus nervi oculomotorii and nucleus nervi trochlear ). About this nerve pathways eye movements are mediated to a noise source reflex.

In a unilateral damage to the core directional hearing is impaired and the hearing of the ear mutual reduced ( hypoacusis ).

Cochlear nucleus posterior

The efferent fibers of the cochlear nucleus posterior cross in the medullary striae also to the opposite side and run in the lateral lemniscus to the contralateral inferior colliculus.