Long Ciliary Nerves - Podcast Version 0:00 / 0:00 1x 0.25x 0.5x 0.75x 1x 1.25x 1.5x 1.75x 2x 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 You've Discovered a Pro Feature Access our 3D Model Library Explore, cut, dissect, annotate and manipulate our 3D models to visualise anatomy in a dynamic, interactive way. Learn More 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: 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. 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. By TeachMeSeries Ltd (2026) Fig 1The 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. Frequent questions What are the long ciliary nerves? The long ciliary nerves are branches of the nasociliary nerve that transmit sensory information from the eyeball and convey sympathetic fibres to the dilator pupillae muscle. They arise from the ophthalmic division of the trigeminal nerve (CN V1) and typically number two or three. What is the course of the long ciliary nerves? The long ciliary nerves originate in the intraconal space of the posterior orbit and run along the medial aspect of the optic nerve. They then enter the posterior part of the eye to supply its structures. What types of fibres do the long ciliary nerves carry? The long ciliary nerves carry sensory fibres from the trigeminal ganglion and sympathetic fibres from the superior cervical ganglion. These fibres serve different functions, with sensory fibres providing sensation and sympathetic fibres innervating the dilator pupillae muscle. What is the sensory supply of the long ciliary nerves? The sensory fibres of the long ciliary nerves provide general sensation to the cornea, iris, and ciliary body. This sensory innervation is crucial for the eye's protective and reflexive functions. How do the long ciliary nerves contribute to pupillary dilation? The long ciliary nerves innervate the dilator pupillae muscle through their sympathetic fibres, which originate from the superior cervical ganglion. This innervation plays a key role in the process of pupillary dilation. Rate This Article