Chapter contents Overview Somatic motor component Origin, central course Intracranial course Final innervation Visceral motor component Origin and course Final innervation

Cranial Nerve III - Oculomotor Nerve Page 11 of 16 Visceral motor component, final innervation Once within the orbit the preganglionic parasympathetic fibers leave the nerve to the inferior oblique muscle to synapse in the ciliary ganglion which lies deep to the superior rectus muscle near the tendinous ring of the extraocular muscles. Postganglionic fibers exit the ciliary ganglion in the short ciliary nerves which enter the posterior aspect of the eye near the point of exit of the optic nerve. Within the eye these fibers travel forward between the choroid and sclera to innervate the ciliary muscles (which control the shape and therefore the refractive power of the lens) and the constrictor pupillae muscle of the iris (which constricts the pupil). Figure 3-11. Visceral motor component, final innervation.

Last revised: March 22, 1998