supratrochlear 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 V₁) 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).{{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}} It arises midway between the base and apex of the orbit where the frontal nerve splits into said terminal branches.

= Course =

The supratrochlear nerve passes medially{{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=42nd |location=New York |pages=782 |oclc=1201341621}} above the trochlea of the superior oblique muscle.{{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}} It then travels anteriorly above the levator palpebrae superioris muscle. It exits the orbit through the supratrochlear notch or foramen. 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.{{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}}

= Branches =

Before exiting the orbit, the supratrochlear nerve emits a descending branch to the infratrochlear nerve.

Function

The supratrochlear nerve provides sensory innervation to the skin and conjunctiva of the upper eyelid, and the skin of the inferomedial forehead.{{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}} It may also provide sensory innervation to part of the periosteum of the frontal bone.{{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}}

Clinical significance

The supratrochlear nerve may be anaesthetised for surgery of parts of the scalp.{{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}}{{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}} This can be used for small lesions of the scalp. It can also be used for more extensive injury to the scalp.{{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}} It is often anaesthetised alongside the supraorbital artery.{{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}}

Etymology

The supratrochlear nerve is named for its passage above the trochlea of the superior oblique muscle.{{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}}

Additional images

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.

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

Category:Ophthalmic nerve