What does Edinger Westphal nucleus do?
The Edinger–Westphal nuclei provide preganglionic input to the ciliary ganglion mediating the pupillary light reflex and accommodation responses of the lens (i.e., the ciliary body).
Where can the Edinger Westphal nucleus be found?
The EWpg is what is thought of as the classic ONC—sending parasympathetic nerve fibers towards the eye. It is located in the midbrain immediately dorsal to the oculomotor nucleus near the level of the superior colliculus, which is why it is often included in the overarching term oculomotor complex.
What is the geniculate ganglion?
The geniculate ganglion is a sensory ganglion of the facial nerve (CN VII). It contains the cell bodies of the fibers responsible for conducting taste sensation from the anterior two-thirds of the tongue.
Is the Edinger Westphal nucleus a part of the sympathetic or parasympathetic nervous system?
The Edinger–Westphal nucleus (accessory oculomotor nucleus) is the parasympathetic pre-ganglionic nucleus that innervates the iris sphincter muscle and the ciliary muscle.
What passes through geniculate ganglion?
The ganglion then sends out nerve fibers to several nerve branches, including: Tympanic (ear) segment of the facial nerve. Greater superficial petrosal nerve. Lesser petrosal nerve.
Is Edinger Westphal nucleus paired?
Location. The paired nuclei are posterior to the main motor nucleus (oculomotor nucleus) and anterolateral to the cerebral aqueduct in the rostral midbrain at the level of the superior colliculus. It is the most rostral of the parasympathetic nuclei in the brain stem.
When are the Edinger Westphal nuclei activated?
When each pretectal nucleus projects bilaterally and synapses in both Edinger-Westphal nuclei (cranial nerve III), the activated Edinger-Westphal nuclei begin the efferent limb of the reflex by generating action potentials.
What is the history of the Edinger nucleus?
The nucleus is named for both Ludwig Edinger, from Frankfurt, who demonstrated it in the fetus in 1885, and for Karl Friedrich Otto Westphal, from Berlin, who demonstrated it in the adult in 1887. The cranial nerve nuclei schematically represented; dorsal view. Motor nuclei in red; sensory in blue.
What is the pathophysiology of a unilateral lesion in the pretectal nucleus?
A unilateral lesion in the pretectal nucleus or in the brachium of the superior colliculus will damage the pupillary fibers coming from the ipsilateral optic tract. This can produce a contralateral RAPD, just like in optic tract lesions, but without any visual loss or visual field defect.