Ophthalmic nerve (English)

The ophthalmic nerve extends in an anterosuperior direction from the trigeminal ganglion and gives rise to a small branch known as the tentorial branch of ophthalmic nerve which provides innervation to the tentorium cerebelli. The frontal nerve is the largest branch of the ophthalmic nerve. It enters the orbit via the superior orbital fissure external to the common tendinous ring and divides into two terminal branches: the supraorbital and supratrochlear nerves. The lacrimal nerve also enters the orbit external to the common tendinous ring and extends across the roof of the orbit towards the lacrimal gland. Before reaching the gland, it expands into several branches, which either terminate in the lacrimal gland or extend through the gland, terminating in the upper eyelid. Just behind the lacrimal gland, the lacrimal nerve is joined by the communicating branch of zygomaticotemporal nerve to lacrimal nerve, which provides parasympathetic innervation to the lacrimal gland. The nasociliary nerve enters the superior orbital fissure within the common tendinous ring and then crosses over to the medial orbital wall. It gives off several branches which include the long ciliary, posterior ethmoidal, anterior ethmoidal and infratrochlear nerves as well as the branch of nasociliary nerve to ciliary ganglion (sensory root of ciliary ganglion).