The infratrochlear nerve is a sensory branch of the nasociliary nerve (itself a branch of the ophthalmic nerve (CN V1)) in the orbit.[1] It courses along the medial wall of the orbit and exits near the medial angle of the eye beneath to the trochlea of superior oblique.[2] It provides sensory innervation to structures at the medial orbit including the skin of the medial eyelids, root of the nose, and parts of the lacrimal sac.[1]:631,783 This nerve is relevant in procedures involving the medial eyelid, lacrimal apparatus, and nasal root.[3]
The infratrochlear nerve provides sensory innervation to the skin of the eyelids, the conjunctiva, lacrimal sac, lacrimal caruncle, and the side of the nose superior to the medial canthus.[1]:631,783
Communications
The infratrochlear nerve receives a descending communicating branch from the supratrochlear nerve.[1]:782
Etymology
The infratrochlear nerve is named after a structure it passes under. Infratrochlear means "below the trochlea". The term trochlea means "pulley" in Latin. Specifically, the trochlea refers to a fibrocartilaginous loop at the superomedial surface of the orbit called the trochlea, through which the tendon of the superior oblique muscle passes.[1]
Additional images
Nerves of the orbit. Seen from above. The infratrochlear nerve is labelled at the top left, and can be seen as a terminal branch of the nasociliary nerve, along with the anterior ethmoidal nerve.
References
12345Standring, Susan (2020). Gray's Anatomy: The Anatomical Basis of Clinical Practice (42thed.). New York. p.631. ISBN978-0-7020-7707-4. OCLC1201341621.{{cite book}}: CS1 maint: location missing publisher (link)
