Editing Pudendal nerve (section)

==Structure==

=== Origin ===
[[File:Gray320.png|thumbnail|Image showing the [[greater sciatic foramen]] (large [[foramen]]), and the [[lesser sciatic foramen]], separated by the [[sacrospinous ligament]]. The pudendal nerve exits the pelvis through the greater sciatic foramen, passes over the ligament, and then reenters the pelvis through the lesser sciatic foramen.]]

The pudendal nerve is paired, meaning there are two nerves, one on the left and one on the right side of the body. Each is formed as three roots immediately converge above the upper border of the [[sacrotuberous ligament]] and the [[coccygeus muscle]].<ref name=Grays /> The three roots become two cords when the middle and lower root join to form the lower cord, and these in turn unite to form the pudendal nerve proper just proximal to the [[sacrospinous ligament]].<ref name=Shafik1995 /> The three roots are derived from the [[ventral rami]] of the 2nd, 3rd, and 4th [[sacral spinal nerves]], with the primary contribution coming from the 4th.<ref name=Grays>{{cite book|last=Standring S (editor in chief)|title=Gray's Anatomy: The Anatomical Basis of Clinical Practice|year=2004|publisher=Elsevier|isbn=978-0-443-06676-4|edition=39th|url-access=registration|url=https://archive.org/details/graysanatomyanat0000unse}}</ref><ref name=Moore215>{{cite book|last=Moore|first=Keith L. Moore, Anne M.R. Agur; in collaboration with and with content provided by Arthur F. Dalley II; with the expertise of medical illustrator Valerie Oxorn and the developmental assistance of Marion E.|title=Essential clinical anatomy|year=2007|publisher=Lippincott Williams & Wilkins|location=Baltimore, MD|isbn=978-0-7817-6274-8|edition=3rd}}</ref>{{rp|215}}<ref name=Russell2006>{{cite book|last=Russell RM|title=Examination of peripheral nerve injuries an anatomical approach|year=2006|publisher=Thieme|location=Stuttgart|isbn=978-3-13-143071-7|url=https://books.google.com/books?id=_NxeENi2lVAC&q=%22pudendal+nerve%22&pg=PA157}}</ref>{{rp|157}}

=== Course and relations ===
The pudendal nerve passes between the [[piriformis muscle]] and [[coccygeus]] (ischiococcygeus) muscles and leaves the pelvis through the lower part of the [[greater sciatic foramen]].<ref name=Grays /> It crosses over the lateral part of the [[sacrospinous ligament]] and reenters the pelvis through the [[lesser sciatic foramen]]. After reentering the pelvis, it accompanies the [[internal pudendal artery]] and [[internal pudendal vein]] upwards and forwards along the lateral wall of the [[ischiorectal fossa]], being contained in a sheath of the [[obturator fascia]] termed the [[pudendal canal]], along with the internal pudendal blood vessels.<ref name=ASCRStextbook />{{rp|8}}

=== Branches ===
Inside the pudendal canal, the nerve divides into branches, first giving off the [[inferior rectal nerve]], then the [[perineal nerve]], before continuing as the [[dorsal nerve of the penis]] (in males) or the [[dorsal nerve of the clitoris]] (in females).<ref name=ASCRStextbook />{{rp|34}}

===Nucleus===
The nerve is a major branch of the [[sacral plexus]],<ref name=Brucker2013>{{cite book|author1=TL King |author2=MC Brucker |author3=JM Kriebs |author4=JO Fahey |title=Varney's midwifery|year=2013|publisher=Jones & Bartlett Publishers|isbn=978-1-284-02542-2|url=https://books.google.com/books?id=dbaNAQAAQBAJ&q=%22pudendal+nerve%22&pg=PA950|edition=Fifth}}</ref>{{rp|950}} with fibers originating in [[Onuf's nucleus]] in the [[sacrum|sacral]] region of the [[spinal cord]].<ref name=Shafik1995 />

===Variation===
The pudendal nerve may vary in its origins. For example, the pudendal nerve may actually originate in the [[sciatic nerve]].<ref>{{cite journal|last=Nayak|first=Soubhagya R.|author2=Madhan Kumar, S.J. |author3=Krishnamurthy, Ashwin |author4=Latha Prabhu, V. |author5=D'costa, Sujatha |author6=Jetti, Raghu|title=Unusual origin of dorsal nerve of penis and abnormal formation of pudendal nerve—Clinical significance|journal=Annals of Anatomy - Anatomischer Anzeiger|date=November 2006|volume=188|issue=6|pages=565–566|doi=10.1016/j.aanat.2006.06.011|pmid=17140150}}</ref> Consequently, damage to the sciatic nerve can affect the pudendal nerve as well. Sometimes [[Dorsal ramus of spinal nerve|dorsal rami]] of the first [[sacral nerve]] contribute fibers to the pudendal nerve, and even more rarely {{abbr|S5|fifth sacral nerve}}.<ref name=Shafik1995>{{cite journal|last=Shafik|first=A|author2=el-Sherif, M |author3=Youssef, A |author4= Olfat, ES |title=Surgical anatomy of the pudendal nerve and its clinical implications|journal=Clinical Anatomy|year=1995|volume=8|issue=2|pages=110–5|pmid=7712320 |doi=10.1002/ca.980080205|s2cid=26706414}}</ref>