Editing Glans penis (section)

==Structure==
[[File:Gray1158.png|thumb|310px|Diagram of the arteries of the penis and its glans]]
[[File:Gray1154.png|thumb|210px|The glans penis as the expansion of the corpus spongiosum]]

The glans penis is a body of spongy [[erectile tissue]] that is moulded on the rounded ends of the two [[Corpus cavernosum penis|corpora cavernosa penis]],<ref name="SchattenConstantinescu2008">{{cite book |last1=Schatten |first1=Heide |url=https://books.google.com/books?id=6iNdSk7gPf4C&q=%22corpus+spongiosum%22+penis&pg=PA10 |title=Comparative Reproductive Biology |last2=Constantinescu |first2=Gheorghe M. |date=21 March 2008 |publisher=John Wiley & Sons |isbn=978-0-470-39025-2}}</ref> extending farther on their upper than on their lower surfaces. It is the expanded cap of the [[corpus spongiosum]],<ref>{{Cite journal |last1=Lee |first1=Shin-Hyo |last2=Ha |first2=Tae-Jun |last3=Koh |first3=Ki-Seok |last4=Song |first4=Wu-Chul |date=2019 |title=Ligamentous structures in human glans penis |journal=Journal of Anatomy |language=en |volume=234 |issue=1 |pages=83–88 |doi=10.1111/joa.12896 |pmid=30450557|pmc=6284436 }}</ref> a sponge-like region that surrounds the male [[urethra]] within the penis maintaining it as a viable channel for [[ejaculation]].<ref>{{Cite web |title=penis {{!}} Description, Anatomy, & Physiology {{!}} Britannica |url=https://www.britannica.com/science/penis |access-date=2022-09-24 |website=www.britannica.com |language=en |archive-date=2022-09-24 |archive-url=https://web.archive.org/web/20220924163237/https://www.britannica.com/science/penis |url-status=live }}</ref> The glans is covered by a [[stratified squamous epithelium]] and a dense layer of [[connective tissue]] equivalent to the [[dermis]] of typical skin.<ref name=":5"/> The papillary layer of the dermis blends into the dense connective tissue forming the [[Tunica albuginea (penis)|tunica albuginea]] of the corpus spongiosum behind the glans.<ref name=":5"/> The external lining with [[Mucous membrane|mucosal tissue]] is responsible for its typical smooth texture and appearance.

The increase of [[Artery|arterial]] flow during [[erection]] fills the erectile tissue with blood causing the glans to grow in size and sensitivity.<ref>{{Cite journal |last1=Dean |first1=Robert C. |last2=Lue |first2=Tom F. |date=2005–2011 |title=Physiology of Penile Erection and Pathophysiology of Erectile Dysfunction |journal=The Urologic Clinics of North America |volume=32 |issue=4 |pages=379–v |doi=10.1016/j.ucl.2005.08.007 |issn=0094-0143 |pmc=1351051 |pmid=16291031}}</ref> While the penis is rigid when erect, the glans itself remains slightly softer.<ref>{{Citation |last1=Hsu |first1=Geng-Long |title=Penis Structure—Erection |date=2018-01-01 |url=https://www.sciencedirect.com/science/article/pii/B9780128012383646032 |encyclopedia=Encyclopedia of Reproduction (Second Edition) |pages=367–375 |editor-last=Skinner |editor-first=Michael K. |access-date=2023-07-06 |place=Oxford |publisher=Academic Press |language=en |isbn=978-0-12-815145-7 |last2=Lu |first2=Hsiu-Chen}}</ref> The soft cushiony texture of the glans absorbs impact during rigorous instances of copulation.<ref>HSU, G‐L., et al. "The distribution of elastic fibrous elements within the human penis." BJU International 73.5 (1994): 566-571.</ref> The proportional size of the glans penis can vary among males. While the shape of the glans is typically acorn-like, in some men it might be wider in circumference than the shaft, giving the penis a mushroom-like appearance, while in others it might be narrower and more akin to a probe in shape.

The reason for the shape of the glans is uncertain. Some researchers have suggested that it evolved to become acorn-, mushroom- or cone-shaped so that, during copulation, it acts to remove any semen from previous sex partners. However, that is not supported when looking at [[primate]] relatives which have different mating behaviors.<ref>Gallup, Gordon G., et al. "[https://www.researchgate.net/profile/Rebecca_Burch2/publication/225573839_Semen_displacement_as_a_sperm_competition_strategy/links/560c1d6508aea68653d354bd.pdf The human penis as a semen displacement device] {{Webarchive|url=https://web.archive.org/web/20180213135141/https://www.researchgate.net/profile/Rebecca_Burch2/publication/225573839_Semen_displacement_as_a_sperm_competition_strategy/links/560c1d6508aea68653d354bd.pdf |date=2018-02-13 }}." Evolution and Human Behavior 24.4 (2003): 277-289</ref><ref>{{cite book|last1=Dixson|first1=Alan F.|title=Sexual Selection and the Origins of Human Mating Systems|date=2009|publisher=OUP Oxford|isbn=978-0-19-156973-9|page=68|url=https://books.google.com/books?id=VRTniKE2liYC&pg=PA68|language=en}}</ref>  

At the summit of the glans is the slit-like vertical external urethral orifice, called the [[urinary meatus]], through which urine, [[semen]] and [[pre-ejaculate|pre-ejaculatory fluid]] exit the penis. The circumference of the base of the glans forms a rounded projecting border, the [[Corona of glans penis|corona glandis]], overhanging a deep retroglandular [[sulcus (morphology)|groove]] known as the ''coronal sulcus''. Behind the corona is the neck of the penis, which separates the glans and the penile shaft. Ventrally, the two glans wings merge on the midline forming the [[septum glandis]] and a triangle or a V-shaped area under it. The [[Penile frenulum|frenulum]] is the highly [[Blood vessel|vascularized]] elastic band of tissue located on the underside of the glans that connects the foreskin to the head of the penis. The frenulum is supple enough to allow the retraction of the foreskin over the glans and pull it back when the erection is gone.<ref>{{Cite web |title=Penis Frenulum: Location, Function & Conditions |url=https://my.clevelandclinic.org/health/body/23533-penis-frenulum |access-date=2022-09-24 |website=Cleveland Clinic |archive-date=2022-09-24 |archive-url=https://web.archive.org/web/20220924163238/https://my.clevelandclinic.org/health/body/23533-penis-frenulum |url-status=live }}</ref> In flaccid state, it tightens to narrow the foreskin opening.<ref name=":1">{{cite web|year=2007|title=Male circumcision: Global trends and determinants of prevalence, safety and acceptability|url=http://whqlibdoc.who.int/publications/2007/9789241596169_eng.pdf|publisher=World Health Organization|access-date=2009-06-12|archive-date=2015-07-15|archive-url=https://web.archive.org/web/20150715135808/http://whqlibdoc.who.int/publications/2007/9789241596169_eng.pdf|url-status=live}}</ref>

=== Innervation ===
The glans and the frenulum are [[nerve|innervated]] by the bilateral [[dorsal nerve of the penis]] and the [[perineal nerve]], both divisions of the [[pudendal nerve]].<ref name=":6">{{Citation |last1=Weech |first1=David |title=Anatomy, Abdomen and Pelvis, Penis Dorsal Nerve |date=2022 |url=http://www.ncbi.nlm.nih.gov/books/NBK525966/ |work=StatPearls |place=Treasure Island (FL) |publisher=StatPearls Publishing |pmid=30247841 |access-date=2022-09-26 |last2=Ameer |first2=Muhammad Atif |last3=Ashurst |first3=John V. |archive-date=2023-04-05 |archive-url=https://web.archive.org/web/20230405190749/https://www.ncbi.nlm.nih.gov/books/NBK525966/ |url-status=live }}</ref> Branches of the dorsal nerve extend through the glans ventrolaterally displaying a three-dimensional innervation pattern.<ref name=":6"/><ref name=":2">{{Cite journal |last1=Yang |first1=Claire C. |last2=Bradley |first2=William E. |date=1999-01-01 |title=Innervation of the human glans penis |url=https://www.auajournals.org/doi/abs/10.1016/S0022-5347(01)62075-5 |journal=Journal of Urology |volume=161 |issue=1 |pages=97–102 |doi=10.1016/S0022-5347(01)62075-5 |pmid=10037378 |access-date=2022-09-24 |archive-date=2021-11-21 |archive-url=https://web.archive.org/web/20211121191429/https://www.auajournals.org/doi/abs/10.1016/S0022-5347%2801%2962075-5 |url-status=live }}</ref> The main branches form smaller bundles of nerves that expand outwards into the tissue of the glans.<ref name=":6"/> The rich innervation of the glans penis reveals its function as a primary anatomical source of male sexual pleasure.<ref name="yangcc"/><ref name=":2"/><ref>{{Cite book |last1=Greenberg |first1=Jerrold |url=https://books.google.com/books?id=1NC5R0RozBYC&pg=PP1 |title=Exploring the Dimensions of Human Sexuality |last2=Bruess |first2=Clint |last3=Conklin |first3=Sarah |date=2010-03-10 |publisher=Jones & Bartlett Learning |isbn=978-0-7637-7660-2 |pages=132 |language=en}}</ref> Yang & Bradley argue; "the distinct pattern of innervation of the glans emphasizes its role as a sensory structure".<ref name="yangcc"/> While Yang & Bradley's (1998) report "showed no areas in the glans to be more densely innervated than others.",<ref name="yangcc">{{cite journal | last = Yang | first = C. C. |author2=W.E. Bradley |date=July 1998 | title = Neuroanatomy of the penile portion of the human dorsal nerve of the penis | journal = British Journal of Urology | volume = 82 | issue = 1 | pages = 109–13 | doi =10.1046/j.1464-410x.1998.00669.x | pmid = 9698671 }}</ref> Halata & Munger (1986) report that the density of several nerve terminals is greatest in the corona glandis.<ref name=":5"/> 

Halata & Spathe (1997) reported: "The glans penis contains a predominance of [[free nerve ending]]s, numerous genital [[bulboid corpuscles|end bulbs]] and rarely [[Pacinian corpuscle|Pacinian]] and [[Bulbous corpuscle|Ruffinian]] corpuscles. [[Merkel nerve ending]]s and [[Meissner's corpuscle]]s ([[mechanoreceptor]]s typically found in thick [[glabrous skin]]) are not present".<ref name="halata2">{{Cite book | last = Halata | first = Zdenek | author2 = A. Spaethe | chapter = Sensory Innervation of the Human Penis | year = 1997 | title = The Fate of the Male Germ Cell | pages = 265–6 | pmid = 9361804 | url = http://www.cirp.org/library/anatomy/halata2/ | access-date = 2006-07-07 | volume = 424 | doi = 10.1007/978-1-4615-5913-9_48 | series = Advances in Experimental Medicine and Biology | isbn = 978-0-306-45696-1 | archive-date = 2006-06-20 | archive-url = https://web.archive.org/web/20060620015859/http://www.cirp.org/library/anatomy/halata2/ | url-status = live }}</ref> The genital end bulbs, that are present throughout the glans, are most numerous in the corona and near the frenulum.<ref name=":5">{{Cite journal |last1=Halata |first1=Z. |last2=Munger |first2=B. L. |date=1986-04-23 |title=The neuroanatomical basis for the protopathic sensibility of the human glans penis |url=https://pubmed.ncbi.nlm.nih.gov/3697758/ |journal=Brain Research |volume=371 |issue=2 |pages=205–230 |doi=10.1016/0006-8993(86)90357-4 |issn=0006-8993 |pmid=3697758 |s2cid=23781274 |access-date=2022-09-25 |archive-date=2022-09-25 |archive-url=https://web.archive.org/web/20220925152126/https://pubmed.ncbi.nlm.nih.gov/3697758/ |url-status=live }}</ref> Simple, Pacinian and Ruffinian corpuscles are identified predominantly in the corona glandis. The most numerous nerve terminals are free nerve endings present in almost every [[dermal papilla]] of the glans, as well as scattered throughout the deeper [[dermis]].<ref name=":5"/> 

=== Blood supply ===
The glans penis receives blood from the [[Internal pudendal artery|internal pudental artery]] through its branch, the [[dorsal artery of the penis]], which also supplies the foreskin, and the [[Body of penis|penile shaft]].<ref>{{Cite book|last1=Clement|first1=Pierre|chapter-url=https://www.sciencedirect.com/science/article/pii/B9780444632470000031|title=Handbook of Clinical Neurology|last2=Giuliano|first2=Francois|publisher=[[Elsevier]]|year=2015|isbn=978-0-444-63247-0|volume=130|pages=19–37|language=en|chapter=3 - Anatomy and physiology of genital organs – men|doi=10.1016/B978-0-444-63247-0.00003-1|pmid=26003237|issn=0072-9752|access-date=2022-10-30|archive-date=2020-10-17|archive-url=https://web.archive.org/web/20201017180739/https://www.sciencedirect.com/science/article/pii/B9780444632470000031|url-status=live}}</ref> Behind the [[Corona of glans penis|corona]], the terminal branches of the dorsal arteries [[Anastomosis|anastomose]] with the axial arteries through perforating branches before they end in the glans.<ref>{{Citation |last=Quartey |first=J. K.M. |title=Anatomy and Blood Supply of the Urethra and Penis |date=2006 |url=https://doi.org/10.1007/3-540-29385-X_3 |work=Urethral Reconstructive Surgery |pages=14 |editor-last=Schreiter |editor-first=F. |place=Berlin, Heidelberg |publisher=Springer |language=en |doi=10.1007/3-540-29385-x_3 |isbn=978-3-540-29385-9 |access-date=2022-10-29 |editor2-last=Jordan |editor2-first=G.H.}}</ref> Branches of the dorsal artery curve around each side of the distal shaft to enter the glans and the frenulum ventrally.<ref>{{Cite journal |last=Hinman |first=F. |date=1991 |title=The blood supply to preputial island flaps |url=https://pubmed.ncbi.nlm.nih.gov/2033699/ |journal=The Journal of Urology |volume=145 |issue=6 |pages=1232–1235 |doi=10.1016/s0022-5347(17)38584-1 |issn=0022-5347 |pmid=2033699 |access-date=2023-01-27 |archive-date=2022-11-09 |archive-url=https://web.archive.org/web/20221109111431/https://pubmed.ncbi.nlm.nih.gov/2033699/ |url-status=live }}</ref> Venous drainage of the penis begins at the base of the glans. Small tributaries deriving from the corona form a venous plexus at the neck of the penis, known as the retro-coronal, or retro-[[wiktionary:balanic|balanic]], plexus.<ref name=":7"/> Smaller paired venules run into the frenulum and the glans from its ventral surface.<ref>{{Cite journal |last=Gyftopoulos |first=Kostis I. |date=2018 |title=Meatal stenosis after surgical correction of short frenulum: Is the "pull-and-burn" method the way to go? |journal=Urology Annals |volume=10 |issue=4 |pages=354–357 |doi=10.4103/UA.UA_25_18 |issn=0974-7796 |pmc=6194789 |pmid=30386085 |doi-access=free }}</ref> The deep dorsal vein, one of the two [[dorsal veins of the penis]], serves as a common vessel receiving blood drained from the glans and the two [[Corpus cavernosum penis|corpora cavernosa]] through the circumflex veins that surround them.<ref name=":7">{{Citation |last=Quartey |first=J. K.M. |title=Anatomy and Blood Supply of the Urethra and Penis |date=2006 |url=https://doi.org/10.1007/3-540-29385-X_3 |work=Urethral Reconstructive Surgery |pages=16 |editor-last=Schreiter |editor-first=F. |place=Berlin, Heidelberg |publisher=Springer |language=en |doi=10.1007/3-540-29385-x_3 |isbn=978-3-540-29385-9 |access-date=2022-10-29 |editor2-last=Jordan |editor2-first=G.H.}}</ref><ref>{{Cite journal |last1=Hsu |first1=Geng-Long |last2=Hsieh |first2=Cheng-Hsing |last3=Wen |first3=Hsien-Sheng |last4=Chen |first4=Yi-Chang |last5=Chen |first5=Shyh-Chyan |last6=Mok |first6=Martin S. |date=2003-11-12 |title=Penile Venous Anatomy: An Additional Description and Its Clinical Implication |journal=Journal of Andrology |language=en |volume=24 |issue=6 |pages=921–927 |doi=10.1002/j.1939-4640.2003.tb03145.x |pmid=14581520 |doi-access=free }}</ref>

===Foreskin===
The glans is completely or partially covered by a double-layered fold of skin, known as the [[foreskin]]. In adults, glans exposure can be easily achieved by manual retraction of the foreskin and sometimes automatically during [[erection]]. The degree of automatic foreskin retraction varies considerably depending on the foreskin length. The foreskin can be characterized as long when the preputial orifice extends beyond the glans during erection, or medium when the orifice is located around the meatus.<ref>{{cite journal |last1=Velazquez |first1=Elsa F. |last2=Bock |first2=Adelaida |last3=Soskin |first3=Ana |last4=Codas |first4=Ricardo |last5=Arbo |first5=Manuel |last6=Cubilla |first6=Antonio L. |year=2003 |title=Preputial variability and preferential association of long phimotic foreskins with penile cancer: An anatomic comparative study of types of foreskin in a general population and cancer patients |journal=The American Journal of Surgical Pathology |volume=27 |issue=7 |pages=994–998 |doi=10.1097/00000478-200307000-00015 |issn=0147-5185 |pmid=12826892 |s2cid=34091663 |url=https://pubmed.ncbi.nlm.nih.gov/12826892/ |url-status=live |access-date=2022-10-29 |archive-url=https://web.archive.org/web/20221108122414/https://pubmed.ncbi.nlm.nih.gov/12826892/ |archive-date=2022-11-08 |df=dmy-all}}</ref> The primary purpose of the foreskin is considered to be the covering of the glans and the [[urinary meatus]],<ref>{{cite book |vauthors = Kirby R, Carson C, Kirby M |year=2009 |title=Men's Health |edition= 3rd |location=New York, NY |publisher=Informa Healthcare |isbn=978-1-4398-0807-8 |oclc=314774041 |page=283}}</ref><ref name=dobanavacki>{{cite journal |vauthors = Dobanovacki D, Lucić Prostran B, Sarac D, Antić J, Petković M, Lakić T|year = 2012 |title = Prepuce in boys and adolescents: What when, and how? |journal = Medicinski Pregled |volume = 65 |issue = 7–8 |pages = 295–300 |pmid = 22924249 |doi = 10.2298/MPNS1208295D |doi-access = free }}</ref> while also maintaining the [[Mucous membrane|mucosa]] in a moist environment.<ref>{{cite journal |last1=Cold |first1=C.J. |last2=Taylor |first2=J.R. |year=1999 |title=The prepuce |journal=BJU International |volume=83 |issue=S1 |pages=34–44 |doi=10.1046/j.1464-410x.1999.0830s1034.x |issn=1464-410X |doi-access=free |pmid=10349413 }}</ref> 

Foreskin rectractability gradually increases with age. In [[infancy]] the foreskin is fused to the glans.<ref>{{cite journal |last1=Dave |first1=Sumit |last2=Afshar |first2=Kourosh |last3=Braga |first3=Luis H. |last4=Anderson |first4=Peter |year=2018 |title=CUA guideline on the care of the normal foreskin and neonatal circumcision in Canadian infants |url=https://cuaj.ca/index.php/journal/article/view/5033 |journal=Canadian Urological Association Journal |language=en |volume=12 |issue=2 |pages=E76–E99 |doi=10.5489/cuaj.5033 |pmid=29381458 |pmc=5937400 |issn=1920-1214 |quote=At birth, the inner foreskin is usually fused to the glans penis and should not be forcibly retracted |access-date=2022-10-29 |archive-date=2022-10-28 |archive-url=https://web.archive.org/web/20221028075921/https://cuaj.ca/index.php/journal/article/view/5033 |url-status=live }}</ref> It remains non-retractable in early [[childhood]] and it continues to be tight during [[preadolescence]].<ref>{{Cite journal |last1=Dave |first1=Sumit |last2=Afshar |first2=Kourosh |last3=Braga |first3=Luis H. |last4=Anderson |first4=Peter |year=2018 |title=CUA guideline on the care of the normal foreskin and neonatal circumcision in Canadian infants |journal=Canadian Urological Association Journal |volume=12 |issue=2 |pages=E76–E99 |lang=en |doi=10.5489/cuaj.5033 |pmid=29381458 |pmc=5937400 |issn=1920-1214 |quote=...&nbsp;the incidence of non-retractable physiological phimosis was 50% in grade&nbsp;1 boys and decreased to 35% in grade&nbsp;4 and 8% in grade&nbsp;7 boys |url=https://cuaj.ca/index.php/journal/article/view/5033 |access-date=2022-10-29 |archive-date=2022-10-28 |archive-url=https://web.archive.org/web/20221028075921/https://cuaj.ca/index.php/journal/article/view/5033 |url-status=live }}</ref> The skin begins to loosen up significantly during [[puberty]] allowing the glans to be completely exposed when needed. By the age of eighteen, most boys will have a fully retractable foreskin.<ref>{{cite journal |last1=McGregor |first1=Thomas B. |last2=Pike |first2=John G. |last3=Leonard |first3=Michael P. |date=2007 |title=Pathologic and physiologic phimosis: Approach to the phimotic foreskin |journal=Canadian Family Physician |lang=en |volume=53 |issue=3 |pages=445–448 |pmid=17872680 |pmc=1949079 |quote="most foreskins will become retractile by adulthood."}}</ref>

In some cases, for [[Circumcision#Society and culture|cultural]], [[Indication (medicine)|medical]], or [[Preventive healthcare|prophylactic]] reasons, some men undergo [[circumcision]] or were circumcised as infants, a procedure in which the foreskin is partially or completely removed from the penis.<ref name=":1"/> The glans of circumcised men remains fully exposed and dry. Several studies have suggested that, generally, the glans of both circumcised and uncircumcised penises are equally sensitive.<ref>{{cite journal |first1=Bleustein |last1=Clifford B. |first2=James D. |last2=Fogarty |first3=Haftan |last3=Eckholdt |first4=Joseph C. |last4=Arezzo |first5=Arnold |last5=Melman |date=April 2005 |title=Effect of neonatal circumcision on penile neurologic sensation |journal=Urology |volume=65 |issue=4 |pages=773–777 |doi=10.1016/j.urology.2004.11.007 |pmid=15833526 }}</ref><ref>{{cite conference |last1=Bleustein |first1=Clifford B. |first2=Haftan |last2=Eckholdt |first3=Joseph C.|last3=Arezzo |first4=Arnold |last4=Melman |title=Effects of circumcision on male penile sensitivity |conference=American Urological Association 98th Annual Meeting |place=Chicago, IL |journal=Clinical Prostate Cancer |year=2003 |volume=2 |issue=1 |pages=8–12 |doi=10.1016/s1540-0352(11)70011-7 |pmid=15046675 |url=http://www.cirp.org/library/sex_function/bleustein2/ |access-date=February 11, 2023 |url-status=live |archive-url=https://web.archive.org/web/20230211152204/http://www.cirp.org/library/sex_function/bleustein2/ |archive-date=February 11, 2023}}</ref><ref>{{cite journal |last1=Payne |first1=Kimberley |last2=Thaler |first2=Lea |last3=Kukkonen |first3=Tuuli |last4=Carrier |first4=Serge |last5=Binik |first5=Yitzchak |date=May 2007 |title=Sensation and sexual arousal in circumcised and uncircumcised men |journal=Journal of Sexual Medicine |volume=4 |issue=3 |pages=667–674 |doi=10.1111/j.1743-6109.2007.00471.x |pmid=17419812}}</ref>