Ciliary ganglion
Ganglion · CN III Orbit
Lies in the posterior orbit between the optic nerve and lateral rectus. Its parasympathetic root from the nerve to inferior oblique (CN III) synapses here; the sympathetic root (internal carotid plexus) and sensory root (nasociliary, V1) pass straight through.
Traced from the start
Detail
- Roots
- Motor (parasympathetic) from inferior division of CN III; sympathetic from the internal carotid plexus; sensory from nasociliary nerve
- Output
- 6–10 short ciliary nerves piercing the sclera around the optic nerve
- Fibre split
- About 95% of postganglionic axons go to the ciliary muscle, only ~5% to sphincter pupillae
When it goes wrong
Viral or idiopathic damage to the ciliary ganglion (or orbital surgery/laser) with aberrant reinnervation
Adie tonic pupil: unilateral dilated pupil that barely reacts to light, constricts slowly to near and redilates slowly; supersensitive to 0.125% pilocarpine; with absent ankle reflexes it is Holmes–Adie syndrome
Practise this structure
4 questions in the bank tagged Cranial Nerves.
A 52-year-old woman has had two months of numbness over the right forehead, the right upper eyelid and the tip of her nose, with a gritty feeling in the right e…
Foundations · middle twist
A 44-year-old man has had 18 months of worsening hearing on the left with constant ringing in that ear. He still follows conversation in a quiet room but cannot…
Foundations · middle twist
A 58-year-old man has sudden vertigo and a hoarse voice, and chokes when he drinks. The palate elevates to the right and there is no gag response when the left…
Foundations · middle twist
A 27-year-old man was struck on the head at football a week ago. He now sees two images, one above the other, worst when reading or going down stairs. The verti…
Foundations · middle twist