{{Short description|Nerve of the forehead}} {{Distinguish|infratrochlear nerve}} {{Infobox nerve | Name = Supratrochlear nerve | Latin = nervus supratrochlearis | Image = Gray784.png | Caption = Sensory areas of the head, showing the general distribution of the three divisions of the fifth nerve. (Supratrochlear nerve labeled at upper left.) | Image2 = Gray776.png | Caption2 = Nerves of the orbit. Seen from above. (Supratrochlear nerve visible near top.) | Innervates = | BranchFrom = Frontal nerve | BranchTo = }} The '''supratrochlear nerve''' is a branch of the frontal nerve, itself a branch of the ophthalmic nerve (CN V<sub>1</sub>) from the trigeminal nerve (CN V). It provides sensory innervation to the skin of the forehead and the upper eyelid.
== Structure ==
=== Origin === The supratrochlear nerve is the smaller of the two terminal branches of the frontal nerve (the other being the supraorbital nerve).<ref name=":0">{{Cite book|last1=Fillmore|first1=Erin P.|chapter-url=https://www.sciencedirect.com/science/article/pii/B9780124103900000238|title=Nerves and Nerve Injuries|last2=Seifert|first2=Mark F.|publisher=Academic Press|year=2015|isbn=978-0-12-410390-0|volume=1: History, Embryology, Anatomy, Imaging, and Diagnostics|pages=319–350|language=en|chapter=22 - Anatomy of the Trigeminal Nerve|doi=10.1016/B978-0-12-410390-0.00023-8}}</ref> It arises midway between the base and apex of the orbit<ref name=":1" /> where the frontal nerve splits into said terminal branches.<ref name=":0" />
=== Course === The supratrochlear nerve passes medially<ref name=":33">{{Cite book |last=Standring |first=Susan |title=Gray's Anatomy: The Anatomical Basis of Clinical Practice |year=2020 |isbn=978-0-7020-7707-4 |edition=42nd |location=New York |pages=782 |oclc=1201341621}}</ref> above the trochlea of the superior oblique muscle.<ref name=":1">{{Cite book|last=Rea|first=Paul|chapter-url=https://www.sciencedirect.com/science/article/pii/B9780128036334000028|title=Essential Clinically Applied Anatomy of the Peripheral Nervous System in the Head and Neck|publisher=Academic Press|year=2016|isbn=978-0-12-803633-4|pages=21–130|language=en|chapter=2 - Head|doi=10.1016/B978-0-12-803633-4.00002-8}}</ref><ref name=":33" /> It then travels anteriorly above the levator palpebrae superioris muscle.<ref name=":0" /> It exits the orbit through the supratrochlear notch or foramen.<ref name=":33" /> It then ascends onto the forehead beneath the corrugator supercilii muscle and frontalis muscle. It finally divides into sensory branches.{{Citation needed|date=January 2023}}
The supratrochlear nerve travels with the supratrochlear artery, a branch of the ophthalmic artery.<ref name=":1">{{Cite book|last=Rea|first=Paul|chapter-url=https://www.sciencedirect.com/science/article/pii/B9780128036334000028|title=Essential Clinically Applied Anatomy of the Peripheral Nervous System in the Head and Neck|publisher=Academic Press|year=2016|isbn=978-0-12-803633-4|pages=21–130|language=en|chapter=2 - Head|doi=10.1016/B978-0-12-803633-4.00002-8}}</ref>
=== Branches === Before exiting the orbit, the supratrochlear nerve emits a descending branch to the infratrochlear nerve.<ref name=":33" /><ref name=":0" />
== Function == The supratrochlear nerve provides sensory innervation to the skin and conjunctiva of the upper eyelid, and the skin of the inferomedial forehead.<ref name=":0">{{Cite book|last1=Fillmore|first1=Erin P.|chapter-url=https://www.sciencedirect.com/science/article/pii/B9780124103900000238|title=Nerves and Nerve Injuries|last2=Seifert|first2=Mark F.|publisher=Academic Press|year=2015|isbn=978-0-12-410390-0|volume=1: History, Embryology, Anatomy, Imaging, and Diagnostics|pages=319–350|language=en|chapter=22 - Anatomy of the Trigeminal Nerve|doi=10.1016/B978-0-12-410390-0.00023-8}}</ref> It may also provide sensory innervation to part of the periosteum of the frontal bone.<ref>{{Cite book|last1=Barral|first1=Jean-Pierre|chapter-url=https://www.sciencedirect.com/science/article/pii/B9780702031007500185|title=Manual Therapy for the Cranial Nerves|last2=Croibier|first2=Alain|publisher=Churchill Livingstone|year=2009|isbn=978-0-7020-3100-7|pages=115–128|language=en|chapter=15 - Ophthalmic nerve|doi=10.1016/B978-0-7020-3100-7.50018-5}}</ref>
== Clinical significance == The supratrochlear nerve may be anaesthetised for surgery of parts of the scalp.<ref name=":2">{{Cite book|last1=Kinder Ross|first1=Alison|chapter-url=https://www.sciencedirect.com/science/article/pii/B978032306612900016X|title=Smith's Anesthesia for Infants and Children|last2=Bryskin|first2=Robert B.|publisher=Mosby (imprint)|year=2011|isbn=978-0-323-06612-9|edition=8th|pages=452–510|language=en|chapter=16 - Regional Anesthesia|doi=10.1016/B978-0-323-06612-9.00016-X}}</ref><ref name=":3">{{Cite book|last=Trott|first=Alexander T.|chapter-url=https://www.sciencedirect.com/science/article/pii/B978032307418600006X|title=Wounds and Lacerations - Emergency Care and Closure|publisher=Saunders|year=2012|isbn=978-0-323-07418-6|edition=4th|language=en|chapter=6 - Infiltration and Nerve Block Anesthesia|pages=41–72 |doi=10.1016/B978-0-323-07418-6.00006-X}}</ref> This can be used for small lesions of the scalp.<ref name=":2" /> It can also be used for more extensive injury to the scalp.<ref name=":3">{{Cite book|last=Trott|first=Alexander T.|chapter-url=https://www.sciencedirect.com/science/article/pii/B978032307418600006X|title=Wounds and Lacerations - Emergency Care and Closure|publisher=Saunders|year=2012|isbn=978-0-323-07418-6|edition=4th|language=en|chapter=6 - Infiltration and Nerve Block Anesthesia|pages=41–72 |doi=10.1016/B978-0-323-07418-6.00006-X}}</ref> It is often anaesthetised alongside the supraorbital artery.<ref name=":2">{{Cite book|last1=Kinder Ross|first1=Alison|chapter-url=https://www.sciencedirect.com/science/article/pii/B978032306612900016X|title=Smith's Anesthesia for Infants and Children|last2=Bryskin|first2=Robert B.|publisher=Mosby (imprint)|year=2011|isbn=978-0-323-06612-9|edition=8th|pages=452–510|language=en|chapter=16 - Regional Anesthesia|doi=10.1016/B978-0-323-06612-9.00016-X}}</ref>
== Etymology == The supratrochlear nerve is named for its passage above the trochlea of the superior oblique muscle.<ref name=":1">{{Cite book|last=Rea|first=Paul|chapter-url=https://www.sciencedirect.com/science/article/pii/B9780128036334000028|title=Essential Clinically Applied Anatomy of the Peripheral Nervous System in the Head and Neck|publisher=Academic Press|year=2016|isbn=978-0-12-803633-4|pages=21–130|language=en|chapter=2 - Head|doi=10.1016/B978-0-12-803633-4.00002-8}}</ref>
== Additional images == <gallery> File:Slide1h.JPG|Supratrochlear nerve File:Slide1abaa.JPG|Extrinsic eye muscle. Nerves of orbita. Deep dissection. File:Slide4abab.JPG|Extrinsic eye muscle. Nerves of orbita. Deep dissection. File:Slide5abab.JPG|Extrinsic eye muscle. Nerves of orbita. Deep dissection. File:Slide6abab.JPG|Extrinsic eye muscle. Nerves of orbita. Deep dissection. File:Slide7abab.JPG|Extrinsic eye muscle. Nerves of orbita. Deep dissection. </gallery>
== References == {{Gray's}} <references />
== External links == * {{SUNYAnatomyFigs|29|02|01}} * {{LoyolaMedEd|GrossAnatomy/h_n/cn/cn1/cnb1.htm}} * {{NormanAnatomy|lesson3}} ({{NormanAnatomyFig|orbit2}}) * {{NormanAnatomy|cranialnerves}} ({{NormanAnatomyFig|V}}) * http://www.dartmouth.edu/~humananatomy/figures/chapter_47/47-2.HTM
{{Trigeminal nerve}} {{Portal bar|Anatomy}} {{Authority control}}
Category:Ophthalmic nerve