Edinger–Westphal nucleus

Edinger–Westphal nucleus
Section through superior colliculus (unlabeled) showing path of oculomotor nerve.
Figure showing the different groups of cells, which constitute, according to Perlia, the nucleus of origin of the oculomotor nerve.
1. Posterior dorsal nucleus.
1’. Posterior ventral nucleus.
2. Anterior dorsal nucleus.
2’. Anterior ventral nucleus.
3. Central nucleus.
4. Nucleus of Edinger and Westphal.
5. Antero-internal nucleus.
6. Antero-external nucleus.
8. Crossed fibers.
9. Trochlear nerve, with 9’, its nucleus of origin, and 9", its decussation.
10. Third ventricle.
M, M. Median line.
Details
PartsProvides input to parasympathetic root of ciliary ganglion
Identifiers
Latinnuclei accessorii nervi oculomotorii
MeSHD065839
NeuroNames498
NeuroLex IDbirnlex_822
Anatomical terms of neuroanatomy

The Edinger–Westphal nucleus also called the accessory or visceral oculomotor nerve, is one of the two nuclei of the oculomotor nerve (CN III) located in the midbrain. It receives afferents from both pretectal nuclei (which have in turn received afferents from the optic tract). It contains parasympathetic pre-ganglionic neuron cell bodies that synapse in the ciliary ganglion. It contributes the autonomic, parasympathetic component to the oculomotor nerve (CN III), ultimately providing innervation to the iris sphincter muscle and ciliary muscle to mediate the pupillary light reflex and accommodation, respectively.

The Edinger–Westphal nucleus has two parts. The first is of preganglionic fibers (EWpg) that terminate in the ciliary ganglion. The second is of centrally projecting cells (EWcp) that project to a number of brainstem structures.