Lacrimal nerve


The lacrimal nerve is the smallest branch of the ophthalmic nerve, itself a branch of the trigeminal nerve. The other branches of the ophthalmic nerve are the frontal nerve and nasociliary nerve.

Structure

The lacrimal nerve branches from the ophthalmic nerve immediately before traveling through the superior orbital fissure to enter the orbit. It travels through it lateral to the frontal nerve outside the annulus of Zinn. After entering, it travels anteriorly along the lateral wall with the lacrimal artery, above the upper margin of the lateral rectus. It receives a communicating branch from the zygomatic nerve which carries the postganglionic parasympathetic axons from the pterygopalatine ganglion. It travels through the lacrimal gland giving sensory and parasympathetic branches to it and then continues anteriorly as a few small sensory branches.

Function

The lacrimal nerve provides sensory innervation to the lacrimal gland, conjunctiva of the lateral upper eyelid and superior fornix, the skin of the lateral forehead, scalp and lateral upper eyelid.
It also provides parasympathetic innervation to the lacrimal gland from the communicating branch it receives from the zygomatic nerve.

Additional images