Infratrochlear nerve
{{Distinguish|supratrochlear nerve}}
The infratrochlear nerve is a branch of the nasociliary nerve (itself a branch of the ophthalmic nerve (CN V1)) in the orbit. It exits the orbit inferior to the trochlea of superior oblique. It provides sensory innervation to structures of the orbit and skin of adjacent structures.{{Cite book |last=Standring |first=Susan |url=https://www.worldcat.org/oclc/1201341621 |title=Gray's Anatomy: The Anatomical Basis of Clinical Practice |year=2020 |isbn=978-0-7020-7707-4 |edition=42th |location=New York |pages=631 |oclc=1201341621}}{{Rp|pages=631, 783}}
{{Infobox nerve
| Name = Infratrochlear nerve
| Latin = nervus infratrochlearis
| Image = Gray784.png
| Caption = Sensory innervation of the head. The infratrochlear nerve is seen in the green area, emerging from the orbit.
| Image2 =
| Caption2 =
| Innervates =Skin of eyelids, conjunctiva, lacrimal sac, lacrimal caruncle, side of nose above medial canthus
| BranchFrom = Nasociliary nerve
| BranchTo =
}}
Structure
The nasociliary nerve terminates by bifurcating into the infratrochlear and the anterior ethmoidal nerves. The infratrochlear nerve travels anteriorly in the orbit along the upper border of the medial rectus muscle and underneath the trochlea of the superior oblique muscle. It exits the orbit medially and divides into small sensory branches.{{Cite book|title=Gray's anatomy : the anatomical basis of clinical practice|others=Standring, Susan|year=2016|isbn=978-0-7020-5230-9|edition=41|location=[Philadelphia]|oclc=920806541}}{{Verify source|date=July 2023|reason=This information is not included in the 42nd edition, so I doubt it was in the 41st (the info about the territory of the nerve was is meanwhile ad verbatim (as in copy-paste) what the 42nd edition says, so I'm guessing the reference was just misplaced).}}
= Distribution =
= Communications =
The infratrochlear nerve receives a descending communicating branch from the supratrochlear nerve.{{Rp|pages=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.
Additional images
File:Gray776.png|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
External links
- {{LoyolaMedEd|GrossAnatomy/h_n/cn/cn1/cnb1.htm}}
- {{NormanAnatomy|cranialnerves}} ({{NormanAnatomyFig|V}})
{{Trigeminal nerve}}
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