Nerve
Ciliary ganglion
Orbital parasympathetic relay for pupil and lens control
High-yield
The parasympathetic relay supplies sphincter pupillae for pupil constriction and ciliary muscle for accommodation. Passing sensory and sympathetic fibers do not relay in this ganglion.
Overview
The ciliary ganglion lies in posterior orbital fat between the optic nerve and lateral rectus. Parasympathetic fibers arriving with CN III synapse here. Short ciliary nerves carry the output toward the eye; sensory and sympathetic fibers pass through without synapsing.
Reference facts
- Origin
- Preganglionic parasympathetic fibers from the Edinger–Westphal region via the inferior division of CN III, commonly with the nerve to inferior oblique
- Course
- Posterior orbit between optic nerve and lateral rectus, anterior to the superior orbital fissure; root arrangement varies
- Motor
- Postganglionic parasympathetic axons in short ciliary nerves to sphincter pupillae and ciliary muscle
- Sensory
- Sensory axons from the globe pass toward nasociliary V1 without synapsing; sympathetic axons from the carotid plexus can also traverse the ganglion
Mnemonic
Calm People Study Often: Ciliary, Pterygopalatine, Submandibular, Otic - the four parasympathetic ganglia of the head.
Clinical correlation
Damage to postganglionic parasympathetic pathways can produce a tonic pupil. During reinnervation, near focusing may cause better, slower constriction than light does. This pattern occurs in Adie pupil and other causes of parasympathetic denervation.
Frequently asked questions
Where does the ciliary ganglion arise?
Preganglionic parasympathetic fibers from the Edinger–Westphal region via the inferior division of CN III, commonly with the nerve to inferior oblique.
What muscles does the ciliary ganglion supply?
The ciliary ganglion supplies the postganglionic parasympathetic axons in short ciliary nerves to sphincter pupillae and ciliary muscle.
What is the sensory distribution of the ciliary ganglion?
Sensory axons from the globe pass toward nasociliary V1 without synapsing; sympathetic axons from the carotid plexus can also traverse the ganglion.
What is the course of the ciliary ganglion?
Posterior orbit between optic nerve and lateral rectus, anterior to the superior orbital fissure; root arrangement varies.