The ciliary ganglion, located within the orbit, carries postganglionic parasympathetic fibers. The preganglionic parasympathetic input to the ciliary ganglion is conveyed via which root?

• A Nasociliary root — sympathetic fibers from the superior cervical ganglion
• B Ophthalmic root — sensory fibers of CN V1
• C Short ciliary nerves directly from the trigeminal ganglion
• D Oculomotor (inferior division) root — preganglionic fibers from Edinger-Westphal nucleus ✓

Explanation

The ciliary ganglion receives its preganglionic parasympathetic input via the oculomotor root, which carries fibers from the Edinger-Westphal (accessory oculomotor) nucleus traveling with CN III's inferior division. Postganglionic fibers then travel via short ciliary nerves to the ciliary muscle (accommodation) and iris sphincter (miosis). The nasociliary root of the ciliary ganglion carries sympathetic fibers (postganglionic, passing through without synapsing) and sensory fibers. Pupillary light reflex arc passes through the ciliary ganglion.

Reference: BD Chaurasia's Human Anatomy, 8th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.