Editing Onuf's nucleus (section)

{{Short description|Group of neurons}}
{{Infobox anatomy
| Name        = Onuf's nucleus
| Latin       = nucleus nervi pudendi
| Image       = Medulla spinalis - Substantia grisea - English.svg
| Caption     = [[Spinal cord]] - [[grey matter]] (Onuf's nucleus not labeled, but region is visible)
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'''Onuf's nucleus''' is a distinct group of [[neuron]]s located in the ventral part ([[Rexed laminae|lamina IX]]) of the [[Anterior horn of spinal cord|anterior horn]] of the [[Sacrum|sacral]] region of the human [[spinal cord]] involved in the maintenance of [[Urinary|micturition]] and [[Defecation|defecatory]] continence, as well as muscular contraction during [[orgasm]]. It contains [[motor neuron]]s, and is the origin of the [[pudendal nerve]]. The sacral region of the spinal cord is the fourth segment (cervical, thoracic, and lumbar being the first three) of vertebrae in the spinal cord which consists of the vertebrae 26-30.<ref name=Mannen>{{cite journal | last = Mannen | first = T | date = 2000 | title = Neuropathological findings of Onuf's nucleus and its significance | journal = Neuropathology | volume = 20 | pages = S30–S3 | doi = 10.1046/j.1440-1789.2000.00298.x | pmid = 11037184 | s2cid = 37675034 }}</ref> While working in New York City in 1899, [[Bronislaw Onuf-Onufrowicz]] discovered this group of unique cells and originally identified it as “Group X.” “Group X” was considered distinct by Onufrowicz because the cells were different in size from the surrounding neurons in the anterolateral group, suggesting that they were independent.<ref name="Onufronwicz B 1899 498–504">{{Citation | doi = 10.1097/00005053-189908000-00006 | author = Onufronwicz B | date = 1899 | title = Notes on the arrangement and function of the cell groups of the sacral region of the spinal cord | url = https://zenodo.org/record/1431989| journal = J Nerv Ment Dis | volume = 26 | issue = 8| pages = 498–504 | s2cid = 147602936 | postscript = . }}</ref>