The long ciliary nerves are nerves of the head region. They are branches of the nasociliary nerve, which itself arises from the ophthalmic division of the trigeminal nerve (CN V1).
They transit sensory information from the eyeball (excluding the conjunctiva) and also convey sympathetic fibres to the dilator pupillae muscle.
Pro Feature - 3D Model
Course
The long ciliary nerves usually number two or three, and arise from the nasociliary nerve within the intraconal space of the posterior orbit (between the globe and the extraocular muscles).
After their origin, they run along the medial aspect of the optic nerve, before entering the posterior aspect of the eye to supply its structures.
They carry two types of fibres, which have different functional origins:
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Sensory fibres – originate from neurons in the trigeminal ganglion. They pass through the ophthalmic division of CN V and the nasociliary nerve to enter the long ciliary nerves.
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Sympathetic fibres – originate from the superior cervical ganglion. They travel in a periarterial plexus surrounding the internal carotid artery, follow the ophthalmic artery, and join the nasociliary nerve before entering the long ciliary nerves.
Fig 1
The long ciliary nerves usually number two or three, and arise from the nasociliary nerve.
Sensory Supply
The sensory fibres of the long ciliary nerves provide general sensation from the cornea, iris, and ciliary body.
Sympathetic Supply
The sympathetic fibres of the long ciliary nerves innervate the dilator pupillae muscle, contributing to pupillary dilation.