{{Short description|Nerve of the head and neck}} {{Distinguish|Suboccipital nerve}} {{Infobox nerve | Name = Lesser occipital nerve | Latin = nervus occipitalis minor | Image = Gray1210.png | Caption = Side of neck, showing chief surface markings. (Lesser occip. nerve labeled at center right.) | Image2 = Gray805.png | Caption2 = The nerves of the scalp, face, and side of neck. (Smaller occipital visible below and to the left of the ear.) | Innervates = Cutaneous innervation of the posterior aspect of the auricle and mastoid region | BranchFrom = Cervical plexus (C2) | BranchTo = }}
The '''lesser occipital nerve''' (or '''small occipital nerve'''<ref name=":2">{{Citation |last1=Yu |first1=Megan |title=Anatomy, Head and Neck, Occipital Nerves |date=2023 |url=https://www.ncbi.nlm.nih.gov/books/NBK542213/ |work=StatPearls |access-date=2023-06-22 |place=Treasure Island (FL) |publisher=StatPearls Publishing |pmid=31194370 |last2=Wang |first2=Shu-Min}}</ref>) is a cutaneous spinal nerve of the cervical plexus.'''<ref name=":0222">{{Cite book |last=Sinnatamby |first=Chummy S. |title=Last's Anatomy |publisher= Elsevier Australia|year=2011 |isbn=978-0-7295-3752-0 |edition=12th |pages=334}}</ref>''' It arises from second cervical (spinal) nerve (C2) (along with the greater occipital nerve). It innervates the skin of the back of the upper neck and of the scalp posterior to the ear.
== Structure == === Origin === It arises from the (lateral branch of the ventral ramus<ref name=":33" /><ref name=":0" />) of cervical spinal nerve C2;<ref name=":33" /><ref name=":0" />'''<ref name=":0222" />''' it (sources differ) receives<ref name=":2" /> or may also receive fibres from cervical spinal nerve C3.<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] |oclc=1201341621}}</ref><ref name=":0">{{Cite book |last=Cesmebasi |first=Alper |chapter-url=https://www.sciencedirect.com/science/article/pii/B9780124103900000329 |title=Nerves and Nerve Injuries |publisher=Academic Press |year=2015 |isbn=978-0-12-410390-0 |volume=1: History, Embryology, Anatomy, Imaging, and Diagnostics |pages=441–449 |language=en |chapter=31 - Anatomy of the Cervical Plexus and Its Branches |doi=10.1016/B978-0-12-410390-0.00032-9}}</ref> It originates between the atlas, and axis.<ref name=":0" />
The lesser occipital nerve is one of the four cutaneous branches of the cervical plexus.<ref name=":1">{{Cite book |last=Rea |first=Paul |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=131–183 |language=en |chapter=3 - Neck |doi=10.1016/B978-0-12-803633-4.00003-X |chapter-url=https://www.sciencedirect.com/science/article/pii/B978012803633400003X}}</ref>
=== Course and relations === It curves around the accessory nerve (CN XI)<ref name=":0" /><ref name=":33" />'''<ref name=":022">{{Cite book |last=Sinnatamby |first=Chummy S. |title=Last's Anatomy |publisher= Elsevier Australia|year=2011 |isbn=978-0-7295-3752-0 |edition=12th |pages=334}}</ref>''' to come to course anterior to it.<ref name=":33" /> It then<ref name=":33" /> curves around<ref name=":0" /> and ascends along the posterior border of the sternocleidomastoid muscle;<ref name=":33" /><ref name=":0" />'''<ref name=":022" />''' rarely, it may pierce the muscle.<ref name=":0" /> Near the cranium, it perforates the deep cervical fascia. It is continued upwards along the scalp posterior to the auricle.<ref name=":33" /><ref name=":0" /> It divides into medial and lateral segments between the inion, and intermastoid line.<ref name=":2" />
=== Branches === It has an auricular, a mastoid, and an occipital branch.<ref name=":2" />
Its auricular branch supplies the skin of the upper and back part of the auricula, communicating with the mastoid branch of the great auricular. This branch is occasionally derived from the greater occipital nerve.{{Citation needed|date=December 2022}}
=== Distribution === The nerve provides sensory innervation to the upper part of the back of the neck and adjacent'''<ref name=":022" />''' scalp posterior to the auricle;'''<ref name=":022" /><ref name=":2" />''' it may also contribute to the sensory innervation of the auricle itself.'''<ref name=":022" />'''
=== Communications === It communicates with the greater occipital nerve,<ref name=":0" /><ref name=":2" /> great auricular nerve, and the auricular branch of the facial nerve.<ref name=":0" />
=== Variation === Rarely, the lesser occipital nerve may be duplicated or triplicated.<ref name=":0" />
== Clinical significance == Problems with the lesser occipital nerve cause occipital neuralgia. Nerve block is difficult due to variation in the course of the nerve.<ref name=":0" />
== Additional images == <gallery> File:Gray784.png|Dermatome distribution of the trigeminal nerve </gallery>
== References == <references />
== External links == * {{SUNYAnatomyFigs|25|03|01}} * http://www.dartmouth.edu/~humananatomy/figures/chapter_47/47-2.HTM {{Webarchive|url=https://web.archive.org/web/20180303181327/http://www.dartmouth.edu/~humananatomy/figures/chapter_47/47-2.HTM |date=2018-03-03 }} * http://www.dartmouth.edu/~humananatomy/figures/chapter_47/47-6.HTM {{Webarchive|url=https://web.archive.org/web/20160504193354/http://www.dartmouth.edu/~humananatomy/figures/chapter_47/47-6.HTM |date=2016-05-04 }}
{{Cervical plexus}} {{Portal bar|Anatomy}} {{Authority control}}
Category:Optic nerve