Ciliary ganglion

Ciliary Ganglion

The ciliary ganglion is a type of parasympathetic ganglion located in the orbit behind the eye and lateral to the optic nerve. It is approximately 2mm in size and receives input from the oculomotor nerve and provides output to the ciliary muscles and constrictor pupillae.

Anatomy

The ciliary ganglion is a small, flattened structure that is suspended by two roots: the sensory root from the nasociliary nerve and the motor root from the inferior division of the oculomotor nerve. The ganglion is located in the posterior part of the orbit. It is situated between the optic nerve and the lateral rectus muscle, closer to the latter.

Function

The ciliary ganglion serves as a relay station for parasympathetic fibers traveling to the eye. It receives preganglionic parasympathetic fibers from the Edinger-Westphal nucleus via the oculomotor nerve. These fibers synapse in the ganglion with postganglionic fibers that innervate the ciliary muscles, which control the shape of the lens, and the constrictor pupillae, which control the size of the pupil.

Clinical significance

Damage to the ciliary ganglion can result in a condition known as Adie's pupil, characterized by a dilated pupil that responds slowly to light but reacts normally to accommodation. Other potential conditions include ophthalmoplegia, ptosis, and anisocoria.

See also

• Parasympathetic nervous system
• Sympathetic nervous system
• Autonomic ganglion
• Oculomotor nerve
• Edinger-Westphal nucleus