Introduction
Ciliary Ganglion
- It is a Parasympathetic ganglion.
- It is a relay station for fibers supplying sphincter pupillae and ciliaris muscle
- It is topographically connected to nasociliary nerve (branch of ophthalmic division of trigeminal nerve)
- It is functionally related to Oculomotor nerve.
Location
It is located near the apex of the orbit between the optic nerve and abducent nerve. Ophthalmic artery is medial to the ganglion
Roots/connections of Ciliary Ganglion
It has three Roots
- Parasympathetic/motor: is derived from nerve to inferior oblique muscle, which is a branch of inferior division of oculomotor nerve.
- Sympathetic: is from T1 spinal segment
- Sensory: is from nasociliary nerve which is a branch of ophthalmic division of trigeminal nerve.nerve
Parasympathetic (Secretomotor) fibers
Preganglionic fibers originate from Edinger -Wesphal nucleus in the midbrain. they pass successively through the oculomotor nerve and its branch to inferior oblique muscle which relays in ciliary ganglion. Postganglionic fibers arise from the ganglion and supply the constrictor(sphincter) pupillae and ciliaris muscle
Sympathetic (mainly vasomotor) fibers
Preganglionic fibers originate from the lateral horn of T1 spinal segment, relay in superior cervical sympathetic ganglion and the postganglionic fibers form plexus around Internal carotid artery and supply dilator pupillae muscle.
Sensory fibers
They reach from the nasociliary branch of ophhtalmic nerve. They pass through the ganglion without relaying.
Branches of Ciliary Ganglion
- Anterior border of ciliary ganglion provides 8-10 short ciliary branches which pierce the sclera around the attachment of optic nerve and pass forward in the space between the sclera and choroid. They contain fibers from all the roots.
- Parasympathetic fibers innervate the sphincter pupillae and ciliaris muscles.
- Sympathetic fibers supply the dilator pupillae muscle.
- Sensory fibers carry general sensations from the eyeball.