Parasympathetic Component of Oculomotor Nerve

Drawing of cranial nerves innervating the orbit, from Miller's Anatomy of the Dog textbook. The oculomotor nerve, which passes through the orbital fissure, conveys somatic efferent axons to four extrinsic eye muscles and parasympathetic preganglionic fibers to the ciliary ganglion. Parasympathetic postganglionic axons from the ciliary ganglion run in short ciliary nerves to reach the iris and ciliary body within the eye. The two intrinsic muscles of the eye are: pupil constrictor m. and ciliary m., the latter functions in lens accommodation for near vision, particularly in primates. The four extrinsic muscles of the eye (plus the levator palpebrae superioris m.) are skeletal muscles innervated by somatic efferent axons from the (non-parasympathetic) oculomotor nucleus. (Note: branches from the pterygopalatine ganglion run through the orbit to innervate the lacrimal gland.)

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