Ciliary Ganglion in a Section of the Skull, Lateral View

Description

Along the lateral wall of the orbit, the ciliary ganglion sits in the posterior orbital apex between the optic nerve (CN II) medially and the lateral rectus muscle laterally, close to the annulus of Zinn. Short ciliary nerves radiate anteriorly from the ganglion toward the posterior sclera, while the long ciliary nerves pass forward without synapsing, tracking with the nasociliary nerve along the superior aspect of the optic nerve. The oculomotor nerve’s inferior division contributes the parasympathetic (preganglionic) motor root to the ganglion, and a sympathetic root arrives via the internal carotid plexus through the ophthalmic artery to join the ciliary nerve network. This lateral sectional perspective matters because it clarifies how a small relay station can influence two high-yield clinical outputs: pupillary constriction and accommodation. Interruption of preganglionic parasympathetic fibers in the inferior division of CN III, or damage to the ciliary ganglion itself, produces a dilated, poorly reactive pupil and loss of near response, while postganglionic injury can present as a tonic (Adie) pupil with segmental sphincter palsy. The spatial relationship to the orbital apex also aligns with patterns seen in orbital apex syndrome, where optic neuropathy and ophthalmoplegia can occur together. Neuroanatomy and ophthalmology teaching blocks use this plate to anchor parasympathetic versus sympathetic pathways to the eye, and to map them onto the optic nerve, extraocular muscles, and the bony confines of the orbit. It also fits well in surgical anatomy references for orbital decompression, endoscopic approaches to the orbital apex, and case-based discussions of anisocoria and third nerve palsy. Anatomical accuracy verified by SciePro's Medical Advisory Board.