The Edinger - Westphal nucleus (nucleus nervi accessory oculomotorii ) is the original core territory of the parasympathetic nerve fibers of the third cranial nerve ( oculomotor nerve ) and is located in the midbrain. It was named after the discoverers Ludwig Edinger and Carl Friedrich Otto Westphal.
This core area controls the pupillary reflex and thus the adaptation of the eye. His afferents relates to the core via the optic nerve and optic tract, these nerve fibers not geniculatum over the lateral corpus, but projected directly into the epithalamus. Here they are switched in the nucleus pretectal on interneurons, which then pull on both sides of the Edinger - Westphal nucleus. Its efferent fibers pull on the ciliary ganglion to the ciliary muscle and Pupillenverenger.
Failure of the Edinger - Westphal nucleus is reflected in a widening of the pupil ( mydriasis) with predominance of the sympathetic nervous system, thus the dilator muscle of the pupil, as well as the inability to Nahakkomodation ( paralysis of the ciliary muscle ). This leads to a light - sensitivity and the inability to see clearly near objects.