Nasociliary nerve

The nasociliary nerve is a branch of the ophthalmic nerve (CN V1; one of three branches of the trigeminal nerve a.k.a. CN V). It is intermediate in size between the two other main branches of the ophthalmic nerve, the frontal nerve and the lacrimal nerve, and is more deeply placed.Base of the skull. Upper surface.Plan of oculomotor nerve.Nerves of the orbit. Seen from above.Distribution of the maxillary and mandibular nerves, and the submaxillary ganglion.The sphenopalatine ganglion and its branches.Dissection showing origins of right ocular muscles, and nerves entering by the superior orbital fissure.Pathways in the ciliary ganglion.Extrinsic eye muscle. Nerves of orbita. Deep dissection.Extrinsic eye muscle. Nerves of orbita. Deep dissection. The nasociliary nerve is a branch of the ophthalmic nerve (CN V1; one of three branches of the trigeminal nerve a.k.a. CN V). It is intermediate in size between the two other main branches of the ophthalmic nerve, the frontal nerve and the lacrimal nerve, and is more deeply placed. The nasociliary nerve enters the orbit between the two heads of the lateral rectus muscles and between the superior and inferior rami of the oculomotor nerve (CN III). It passes across the optic nerve (CN II) and runs obliquely beneath the superior rectus muscle and superior oblique muscle to the medial wall of the orbital cavity. It passes through the anterior ethmoidal opening as the anterior ethmoidal nerve and enters the cranial cavity just below the cribriform plate of the ethmoid bone. It supplies branches to the mucous membrane of the nasal cavity and finally emerges between the inferior border of the nasal bone and the side nasal cartilages as the external nasal branch. A branch of the ophthalmic nerve in the superior orbital fissure, passing through the orbit, giving rise to the communicating branch to the ciliary ganglion, the long ciliary nerves, the posterior and anterior ethmoidal nerves, and terminating as the infratrochlear and nasal branches, which supply the mucous membrane of the nose, the skin of the tip of the nose, and the conjunctiva.