Ciliary ganglion

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The ciliary ganglion is small parasympathetic ganglion lying in the orbit between the optic nerve and the lateral rectus muscle that is associated with the nasociliary nerve (a branch of the ophthalmic division of the trigeminal nerve). The ciliary ganglion is a part of the nervous pathway responsible for the constriction of the pupil and accommodation for image focusing, as well as sensation from the cornea.

It receives presynaptic fibers from the Edinger-Westphal nucleus by way of the oculomotor nerve (CN III), and, in turn, gives rise to postsynaptic fibers that innervate the ciliary muscle and the sphincter pupillae muscle.

It also receives the Sympathetic Root, which is a series of fibers coming from the Budge Cilio-Spinal tract, coming from the sympathetic ganglia in C8-T2, which carries the nervous fibers that innervate the iris dilator muscle.

[edit] Roots

It receives three roots:

• (1) sensory fibers that come directly from the nasociliary nerve, and do not synapse in the ganglion;
• (2) sympathetic fibers that come from the plexus associated with the internal carotid artery and the ophthalmic artery, and do not synapse in the ganglion;
• (3) presynaptic parasympathetic fibers from the inferior division of the oculomotor nerve (CNIII, Edinger-Westphal nucleus). The parasympathetic fibers synapse within the ganglion.

[edit] Paths

The postganglionic fibers travel via the short ciliary nerve. These include:

• (1) general sensory to the eye;
• (2) sympathetic fibers to the dilator pupillae;
• (3) parasympathetic fibers to the sphincter pupillae and ciliary muscles of the eye.

[edit] Additional images

thumb|Plan of oculomotor nerve.

The right sympathetic chain and its connections with the thoracic, abdominal, and pelvic plexuses.

Diagram of efferent sympathetic nervous system.

Sympathetic connections of the ciliary and superior cervical ganglia.

[edit] External links

• SUNY Figs 29:03-04 - "A deeper dissection of the right orbit from a superior approach."
• Atlas of anatomy at UMich n2a4p2 - "Branches of Trigeminal Nerve, Lateral View"

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