View source for Genital tubercle

{{Short description|Body of tissue present in the development of the reproductive system}}
{{Infobox embryology
| Name          = Genital tubercle
| Latin         = tuberculum phallicum; tuberculum genitale
| Image         = Human genitalia - development 1.png
| Caption       = Stages in the development of the external sexual organs in the male and female.
| Image2        =
| Caption2      =
| System        = [[Reproductive system]]
| CarnegieStage =
| Precursor     = [[Somatopleure]]<ref name="isbn0-914168-99-1">{{cite book |author1=Netter, Frank H. |author2=Cochard, Larry R. |title=Netter's Atlas of human embryology |publisher=Icon Learning Systems |location=Teterboro, N.J |year=2002 |isbn=0-914168-99-1 |page=159}}</ref>
| GivesRiseTo   = [[Clitoris]] or [[penis]]
}} 
A '''genital tubercle''', '''phallic tubercle''', '''clitorophallic structure''',<ref>{{cite book|last=Skinner|first=Michael K.|publisher=Elsevier Science|year= 2018|title= Encyclopedia of Reproduction: Volume 1 |page=445|isbn=978-0-12815-145-7|url=https://books.google.com/books?id=m4RlDwAAQBAJ&pg=RA3-PA445}}</ref> or simply a '''phallus''' is a body of tissue present in the [[development of the reproductive system]] of [[amniote]]s.<ref>{{cite book|last=Prum|first=Richard O.|publisher = University of Chicago Press|year=2023|title= Performance All the Way Down: Genes, Development, and Sexual Difference |page=219|isbn= 978-0-22682-978-4 |url=https://books.google.com/books?id=9KTMEAAAQBAJ&pg=PA219}}</ref> It forms in the ventral, caudal region of [[mammal]]ian [[embryo]]s of both [[sex]]es, and eventually develops into a [[primordial phallus]]. In the human [[fetus]], the genital tubercle develops around week four of [[gestation]], and by week nine, becomes recognizably either a [[clitoris]] or [[Human penis|penis]]. This should not be confused with the [[sinus tubercle]] which is a proliferation of [[endoderm]] induced by paramesonephric ducts. Even after the phallus is developed (either a [[Body of penis|penile shaft]] or [[Clitoris#Body|clitoral shaft]]),<ref>{{cite book|last=Netter|first=Frank|publisher = Elsevier Health Sciences |year=2022|title=Netter Atlas of Human Anatomy: Classic Regional Approach - Ebook|page=194|access-date=October 9, 2023 |isbn= 978-0-32379-375-9 |url=https://books.google.com/books?id=-ydgEAAAQBAJ&dq=%E2%80%9Cgenital+tubercle%E2%80%9D+%E2%80%9Cshaft%E2%80%9D+%E2%80%9Cglans%E2%80%9D+%E2%80%9Cclitoris%E2%80%9D&pg=RA1-PA194}}</ref> the term genital tubercle remains, but only as the terminal end of it,<ref name="e024">{{Cite web |title=Urogenital Development - External Genitalia 24 of 28 |url=http://www.med.unc.edu/embryo_images/unit-genital/genital_htms/genital024.htm |url-status=live |archive-url=https://web.archive.org/web/20110411041212/http://www.med.unc.edu/embryo_images/unit-genital/genital_htms/genital024.htm |archive-date=Apr 11, 2011 |website=Units of Embryo Images |publisher=UNC School of Medicine}}</ref> which develops into either the [[glans penis]] or the [[Clitoris#Glans|glans clitoridis]].

In the development of the male fetus, the two sides of the tubercle approach ventrally forming a hollow tube that encloses the [[male urethra]]. The two glans wings merge in the midline forming the [[septum glandis]].<ref>{{Citation |last1=Joseph |first1=Diya B. |title=Male Reproductive Tract: Development Overview |date=2018 |url=https://books.google.com/books?id=m4RlDwAAQBAJ&pg=PA248 |encyclopedia=Encyclopedia of Reproduction |pages=248–255 |publisher=Elsevier |language=en |doi=10.1016/B978-0-12-801238-3.64366-0 |access-date=2023-01-04 |last2=Vezina |first2=Chad M.|isbn=9780128151457 |url-access=subscription }}</ref> In the female fetus, the tubercle is attached to the vestibular folds that remain unfused forming the [[labia minora]] and the [[Vulval vestibule|vaginal vestibule]] in between.<ref>{{Cite journal |last1=Baskin |first1=Laurence |last2=Shen |first2=Joel |last3=Sinclair |first3=Adriane |last4=Cao |first4=Mei |last5=Liu |first5=Xin |last6=Liu |first6=Ge |last7=Isaacson |first7=Dylan |last8=Overland |first8=Maya |last9=Li |first9=Yi |last10=Cunha |first10=Gerald R. |date=2018 |title=Development of the human penis and clitoris |journal=Differentiation; Research in Biological Diversity |volume=103 |pages=74–85 |doi=10.1016/j.diff.2018.08.001 |issn=1432-0436 |pmc=6234061 |pmid=30249413}}</ref> The genital tubercle is sensitive to [[dihydrotestosterone]] and rich in [[5-alpha-reductase]], so that the amount of fetal [[testosterone]] present after the second month is a major determinant of phallus size at birth.

==See also==
*[[Clitorophallus]]
*[[Sexual differentiation]]

==References==
{{Reflist}}

==External links==
* {{EmbryologySwiss|ugenital/genitexterne01}}
* [https://web.archive.org/web/20060429053315/http://sprojects.mmi.mcgill.ca/embryology/ug/Reproductives/Normal/Male_external.html Overview at mcgill.ca]

{{Development of urinary and reproductive systems}}
{{Authority control}}

{{DEFAULTSORT:Genital Tubercle}}
[[Category:Embryology of urogenital system]]