After relay in the superior cervical ganglion, postganglionic sympathetic fibres destined for the dilator pupillae reach the eye by travelling through which structure within the orbit?
- A Short ciliary branches of the ciliary ganglion
- B Long ciliary branches of the nasociliary nerve ✓
- C Zygomaticotemporal nerve to the lacrimal nerve
- D Frontal nerve along the orbital roof
Correct answer: B. Long ciliary branches of the nasociliary nerve
Explanation
Sympathetic fibres ascend from the superior cervical ganglion along the internal carotid artery as the internal carotid plexus, pass through the ciliary ganglion without synapsing, and join the nasociliary nerve, whose long ciliary nerves deliver them to the dilator pupillae. Short ciliary nerves carry postganglionic parasympathetic fibres from the ciliary ganglion plus sympathetic and sensory fibres en route to the globe, so they are a tempting but incorrect choice here.
Reference: Gray's Anatomy for Students, 4th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
Written and medically reviewed by the StethoPrep medical team.