Edinger–Westphal nucleus
The Edinger–Westphal nucleus (accessory oculomotor nucleus, or visceral oculomotor nucleus) is one of two nuclei of the oculomotor nerve and is located in the midbrain. It receives afferents from the 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.
| 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 | |
| Parts | Provides input to Parasympathetic root of ciliary ganglion |
| Identifiers | |
| Latin | nuclei accessorii nervi oculomotorii |
| MeSH | D065839 |
| NeuroNames | 498 |
| NeuroLex ID | birnlex_822 |
| Anatomical terms of neuroanatomy | |
The term "Edinger–Westphal nucleus" also referred to what is now known as the centrally-projecting Edinger–Westphal nucleus, intermingled population of non-preganglionic neurons that do not project to the ciliary ganglion but to various regions throughout the central nervous system.