Abducens nerve

The abducens nerve is the VI. Cranial nerve. It consists predominantly of motor fibers and innervates the lateral rectus muscle ( " Lateral Rectus Muscle " ) on the eye, where the eye axis moved to the side ( in the jargon " abducted ", hence the name of the nerves). In birds, it also innervates the nictitating membrane muscles (musculus quadratus membranae nicitantis and musculus pyramidalis membranae nicitantis ).

Course

The core area (nucleus nervi abducentis ) is located in the pontine tegmentum ( pontine tegmentum ). He runs over the clivus of the occipital bone and reaches the cavernous sinus which he runs through and then through the superior orbital fissure ( in artiodactyls: foramen orbitorotundum, other animals: orbital fissure ) in the orbit and the tendinous communis draw. In addition to the lateral rectus muscle, he also supplies the lateral aspect of the musculus retractor bulbi ( only in animals ).

Lesion

A paralysis of the abducens nerve is called the sixth nerve palsy. As a result of the unperturbed tone of the rectus medialis, the opponent of the lateral rectus muscle, there is a squint. The abducens nerve has the longest extradural course of the optic nerve and can therefore easily be violated if there is a fracture of the skull. In addition, he is also damaged when bleeding occurs in the subarachnoid space. As a result of a lumbar puncture the pressure of the cerebrospinal fluid inside the skull, which can lead to a tensile load of the nervus abducens drops.