Human penis#Terminology

File:Penis lateral cross section.jpg

Three main parts of the human penis include:

• Root: It is the attached part, consisting of the bulb in the middle and the crura, one crus on either side of the bulb. It lies within the superficial perineal pouch. The crus is attached to the pubic arch.
• Shaft: The pendulous part of the penis. It has two surfaces: dorsal (posterosuperior in the erect penis) and ventral or urethral (facing downwards and backwards on the flaccid penis). The ventral surface is marked by the penile raphe. The base of the shaft is supported by the suspensory ligament, which is attached to the pubic symphysis.{{cite book|author1=Richard L. Drake|author2=A. Wayne Voglz|author3=Adam W. M. Mitchell|title=Gray's anatomy for students fourth edition|date=8 March 2019|publisher=Elsevier|isbn=978-0323393041|page=461,501,502}}
• Epithelium of the penis consists of the shaft skin, the foreskin (prepuce), and the preputial mucosa on the inside of it. The foreskin covers and protects the glans and shaft. The epithelium is not attached to the underlying shaft, so it is free to glide to and fro.{{cite web|url=http://www.circumstitions.com/completeman/sidegif.gif|title=Video of gliding action|website=Circumstitions|access-date=July 17, 2022|archive-date=May 7, 2017|archive-url=https://web.archive.org/web/20170507142948/http://www.circumstitions.com/completeman/sidegif.gif|url-status=live}}

The human penis is made up of three columns of erectile tissue: two corpora cavernosa lie next to each other (separated by a fibrous septum) on the dorsal side and one corpus spongiosum lies between them on the ventral side.{{cite book|title=Bannister LH, Dyson M. Reproductive system. In: Williams PL, ed. Gray's Anatomy. London: Churchill Livingstone; 1995:1857.|oclc = 45217979}} These columns are surrounded by a fibrous layer of connective tissue called the tunica albuginea. The corpora cavernosa are innervated by lesser and greater cavernous nerves and form most of the penis containing blood vessels that fill with blood to help make an erection.{{cite web|url=http://www.cancer.gov/publications/dictionaries/cancer-terms/def/corpus-cavernosum|title=corpus cavernosum|date=Feb 2011|publisher=U.S.gov|access-date=13 Feb 2022|archive-date=13 February 2022|archive-url=https://web.archive.org/web/20220213062929/https://www.cancer.gov/publications/dictionaries/cancer-terms/def/corpus-cavernosum|url-status=live}}

The crura are the proximal parts of the corpora cavernosa. The corpus spongiosum is an erectile tissue surrounding the urethra. The proximal parts of the corpus spongiosum form the bulb and the distal ends form the glans penis.

The enlarged and bulbous-shaped end of the corpus spongiosum forms the glans penis with two specific types of sinusoids, which supports the foreskin, a loose fold of skin that in adults can retract to expose the glans.{{cite journal|title=The distribution of elastic fibrous elements within the human penis |journal=British Journal of Urology|volume=73|issue=5|pages=566–571 |pmid=8012781 |date=May 1994|vauthors=Hsu GL, Brock G, von Heyden B, Nunes L, Lue TF, Tanagho EA|doi=10.1111/j.1464-410X.1994.tb07645.x}} The area on the underside of the glans, where the foreskin is attached, is called the frenulum. The rounded base of the glans is called the corona. The inner surface of the foreskin and corona is rich in sebaceous glands that secrete smegma. The structure of the penis is supported by the pelvic floor muscles.

File:Gray1158_cumpleted.png

The urethra, which is the last part of the urinary tract, traverses the corpus spongiosum (spongy urethra) and opens through the urinary meatus on the tip of the glans.

File:1116 Muscle of the Male Perineum.png

The penile raphe is the visible ridge between the lateral halves of the penis, found on the ventral or underside of the penis, running from the meatus and continuing as the perineal raphe across the scrotum and the perineum (area between scrotum and anus).{{cite book|url=https://trove.nla.gov.au/work/20029471|title=Snell RS. The perineum. In: Snell RS, ed. Clinical Anatomy. Philadelphia, Pa: Lippincott Williams & Wilkins; 2004:430–431.|publisher=Baltimore, MD Lippincott Williams & Wilkins|isbn=9780781791649|year=2006|access-date=2019-01-17|archive-date=2019-01-19|archive-url=https://web.archive.org/web/20190119120952/https://trove.nla.gov.au/work/20029471|url-status=live}}

The human penis differs from those of most other mammals, as it has no baculum (or erectile bone) and instead relies entirely on engorgement with blood to reach its erect state. A distal ligament buttresses the glans penis and plays an integral role to the penile fibroskeleton, and the structure is called "os analog", a term coined by Geng Long Hsu in the Encyclopedia of Reproduction.{{cite book

|url=https://www.elsevier.com/books/encyclopedia-of-reproduction/skinner/978-0-12-811899-3

|title=M. K. Skinner (Ed.), Encyclopedia of Reproduction. vol. 1, pp. 367–375. Academic Press: Elsevier.

|date=29 June 2018

|publisher=Academic Press

|isbn=978-0-12-811899-3

|access-date=2019-01-17

|archive-date=2021-02-22

|archive-url=https://web.archive.org/web/20210222234452/https://www.elsevier.com/books/encyclopedia-of-reproduction/skinner/978-0-12-811899-3

|url-status=live

}} It is a remnant of the baculum that has likely evolved due to change in mating practice.{{cite web|url=https://www.science.org/content/article/why-humans-lost-their-penis-bone|title=Why Humans Lost Their Penis Bone|date=13 December 2016|publisher=Science|access-date=30 June 2022|archive-date=19 June 2022|archive-url=https://web.archive.org/web/20220619130041/https://www.science.org/content/article/why-humans-lost-their-penis-bone|url-status=live}}

The human penis cannot be withdrawn into the groin, and it is larger than average in the animal kingdom in proportion to body mass. The human penis is reciprocating from a cotton soft to a bony rigidity resulting from penile arterial flow varied between 2–3 to 60–80 mL/Min implies the most ideal milieu to apply Pascal's law in the entire human body; the overall structure is unique.

{{Main|Human penis size}}

Penile measurements vary, with studies that rely on self-measurement reporting a significantly higher average size than those which rely on measurements taken by health professional. A 2015 systematic review of 15,521 men in which the subjects were measured by health professionals showed that the average length of an erect human penis is 13.12 cm (5.17 inches) long, while the average circumference of an erect human penis is 11.66 cm (4.59 inches).

Among all primates, the human penis is the largest in girth, but is comparable to the chimpanzee penis and the penises of certain other primates in length.{{cite book | author = Dixson, A. F. | year = 2009 | title = Sexual selection and the origins of human mating systems | publisher = Oxford University Press | pages = 61–65 | url = https://books.google.com/books?id=VRTniKE2liYC| isbn = 9780191569739 }} Penis size is affected by genetics, but also by environmental factors such as fertility medications{{cite news|last=Center of Disease Control|title=DES Update: Consumers|url=https://www.cdc.gov/des/consumers/about/effects_sons.html|access-date=2013-11-07|archive-date=2014-03-17|archive-url=https://web.archive.org/web/20140317014942/http://www.cdc.gov/DES/CONSUMERS/about/effects_sons.html|url-status=live}}{{medrs|date=November 2024|reason=WP:MEDDATE}} and chemical/pollution exposure.{{Cite journal|doi=10.1289/ehp.8100 |vauthors=Swan SH, Main KM, Liu F, etal |title=Decrease in anogenital distance among male infants with prenatal phthalate exposure |journal=Environmental Health Perspectives |volume=113 |issue=8 |pages=1056–61 |date=August 2005 |pmid=16079079 |pmc=1280349 |bibcode=2005EnvHP.113.1056S }}{{medrs|date=November 2024|reason=WP:MEDDATE}}{{cite web | url = http://discovermagazine.com/1996/sep/hormonehell865/ | work = DISCOVER | title = Hormone Hell | access-date = 2008-04-05 | archive-date = 2009-08-13 | archive-url = https://web.archive.org/web/20090813151600/http://discovermagazine.com/1996/sep/hormonehell865/ | url-status = live }}{{medrs|date=November 2024}}

File:Penis collage.jpg

• Pearly penile papules are raised bumps of somewhat paler color around the base (sulcus) of the glans, which typically develop in males aged 20 to 40. As of 1999, different studies had produced estimates of incidence ranging from 8 to 48 percent of all men.{{cite web

|url=http://emedicine.medscape.com/article/1058826-overview#a0199

|title=Pearly Penile Papules: Epidemiology

|website=Medscape

|last=Brown

|first=Clarence William

|date=February 13, 2014

|access-date=2014-03-08

|archive-date=2010-02-15

|archive-url=https://web.archive.org/web/20100215010922/http://emedicine.medscape.com/article/1058826-overview#a0199

|url-status=live

}}{{medrs|date=November 2024|reason=WP:MEDDATE}} They may be mistaken for warts, but are not harmful or infectious and do not require treatment.{{cite web|url=http://www.netdoctor.co.uk/menshealth/facts/spotsonthepenis.htm|title=Spots on the penis|work=Netdoctor |date=3 November 2014|access-date=16 January 2017|archive-date=20 December 2008|archive-url=https://web.archive.org/web/20081220104739/http://www.netdoctor.co.uk/menshealth/facts/spotsonthepenis.htm|url-status=live}}{{medrs|date=November 2024}}

• Fordyce's spots are small, raised, yellowish-white spots 1–2 mm (roughly 0.05 inch) in diameter that may appear on the penis, which again are common and not infectious.
• Sebaceous prominences are raised bumps similar to Fordyce's spots on the shaft of the penis, located at the sebaceous glands and are normal.
• Phimosis is an inability to retract the foreskin fully. It is normal and harmless in infancy and pre-pubescence, occurring in about 8% of boys at age 10. According to the British Medical Association, treatment (topical steroid cream and/or manual stretching) does not need to be considered until age 19.
• Curvature: few penises are completely straight, with curves commonly seen in all directions (up, down, left, right). Sometimes the curve is very prominent but it rarely inhibits sexual intercourse. Curvature as great as 30° is considered normal and medical treatment is rarely considered unless the angle exceeds 45°. Changes to the curvature of a penis may be caused by Peyronie's disease.

{{main|Development of the reproductive system}}

File:Human genitalia - development 1.png from indifferent to both sexes - male on left]]

When the fetus is exposed to testosterone, the genital tubercle elongates (primordial phallus) and develops into the glans and shaft of the penis and the urogenital folds fuse to become the penile raphe.Keith L. Moore, T. V. N. Persaud, Mark G. Torchia, The Developing Human: Clinically Oriented Embryology 10th Ed. Elsevier Health Sciences, 2015 {{ISBN|9780323313483}}, [https://books.google.com/books?id=pmKGBwAAQBAJ&pg=PA267 pp 267-69]{{cite book |last1=Jones |first1=Richard E. |url=https://books.google.com/books?id=M4kEdSnS-pkC&pg=352 |title=Human Reproductive Biology |last2=Lopez |first2=Kristin H. |date=28 September 2013 |publisher=Academic Press |isbn=978-0-12-382185-0 |page=352}}{{cite book|last1=Martin|first1=Richard J.|last2=Fanaroff|first2=Avory A.|last3=Walsh|first3=Michele C.|publisher=Elsevier Health Sciences|year=2014|title=Fanaroff and Martin's Neonatal-Perinatal Medicine E-Book: Diseases of the Fetus and Infant|page=1522|access-date=November 24, 2023|isbn=978-0-32329-537-6|url=https://books.google.com/books?id=AnVYBAAAQBAJ&pg=PA1522|archive-date=November 24, 2023|archive-url=https://web.archive.org/web/20231124133320/https://books.google.com/books?id=AnVYBAAAQBAJ&pg=PA1522&dq=|url-status=live}} The urethra within the penis (except within the glans) is developed from the urogenital sinus.{{cite book|last=Kulkarni|first=Neeta V|publisher= Jaypee Brothers Medical Publishers Pvt. Limited|year=2015|title= Clinical Anatomy: A Problem Solving Approach |page=653|isbn= 978-9-35152-966-8 |url= https://books.google.com/books?id=vrlEDwAAQBAJ&pg=PA653}}

{{See also|Tanner stages}}

On entering puberty, the penis, scrotum and testicles will enlarge toward maturity. During the process, pubic hair grows above and around the penis. A large-scale study assessing penis size in thousands of 17- to 19-year-old males found no difference in average penis size between 17-year-olds and 19-year-olds. From this, it can be concluded that penile growth is typically complete not later than age 17, and possibly earlier.{{Cite journal|vauthors=Ponchietti R, Mondaini N, Bonafè M, Di Loro F, Biscioni S, Masieri L |s2cid=46856727 |title=Penile length and circumference: a study on 3,300 young Italian males |journal=European Urology |volume=39 |issue=2 |pages=183–6 |date=February 2001 |pmid=11223678 |doi=10.1159/000052434}}{{medrs|date=November 2024|reason=WP:MEDDATE}}

{{Main|Urination}}

Males expel urine from the bladder through the urethra, which passes through the prostate where it is joined by the ejaculatory ducts, and then onward through the penis. At the root of the penis (the proximal end of the corpus spongiosum) lies the external sphincter muscle. This is a small sphincter of striated muscle tissue and is in healthy males, under voluntary control. Relaxing the urethral sphincter allows the urine in the upper urethra to enter the penis properly and thus empty the urinary bladder.

Physiologically, urination involves coordination between the central, autonomic, and somatic nervous systems. In infants, some elderly individuals, and those with neurological injury, urination may occur as an involuntary reflex. Brain centers that regulate urination include the pontine micturition center, periaqueductal gray, and the cerebral cortex.{{cite journal |vauthors=Sie JA, Blok BF, de Weerd H, Holstege G |title=Ultrastructural evidence for direct projections from the pontine micturition center to glycine-immunoreactive neurons in the sacral dorsal gray commissure in the cat |journal=J. Comp. Neurol. |volume=429 |issue=4 |pages=631–7 |year=2001 |pmid=11135240 |doi=10.1002/1096-9861(20010122)429:4<631::AID-CNE9>3.0.CO;2-M|s2cid=7570375 }}{{medrs|date=November 2024|reason=WP:MEDDATE}} During erection, these centers block the relaxation of the sphincter muscles, so as to act as a physiological separation of the excretory and reproductive function of the penis, and preventing urine from entering the upper portion of the urethra during ejaculation.{{cite journal|last=Schirren|first=C.|author2=Rehacek, M. |author3=Cooman, S. de |author4= Widmann, H.-U. |title=Die retrograde Ejakulation|journal=Andrologia|date=24 April 2009|volume=5|issue=1|pages=7–14|doi=10.1111/j.1439-0272.1973.tb00878.x|s2cid=83926005|doi-access=free}}{{medrs|date=November 2024|reason=WP:MEDDATE}}

The distal section of the urethra allows a human male to direct the stream of urine by holding the penis. This flexibility allows the male to choose the posture in which to urinate. In cultures where more than a minimum of clothing is worn, the penis allows the male to urinate while standing without removing much of the clothing. It is customary for some boys and men to urinate in seated or crouched positions. The preferred position may be influenced by cultural or religious beliefs.{{cite web|url=http://www.mednet.nl/wosmedia/1718/mictiehouding_tvu.pdf|title=Influence of voiding posture on urodynamic parameters in men: a literature review|author1=Y. de Jong|author2=R.M. ten Brinck|author3=J.H.F.M. Pinckaers|author4=A.A.B. Lycklama à Nijeholt|publisher=Nederlands Tijdschrift voor urologie|access-date=2014-07-02|archive-date=2014-07-14|archive-url=https://web.archive.org/web/20140714200739/http://www.mednet.nl/wosmedia/1718/mictiehouding_tvu.pdf|url-status=live}} Research on the medical superiority of either position exists, but the data are heterogenic. A meta-analysis{{cite journal|last1=de Jong|first1=Y|last2=Pinckaers|first2=JH|last3=Ten Brinck|first3=RM|last4=Lycklama À Nijeholt|first4=AA |last5=Dekkers|first5=OM |title=Urinating Standing versus Sitting: Position Is of Influence in Men with Prostate Enlargement. A Systematic Review and Meta-Analysis.|journal=PLOS ONE|date=2014|volume=9|issue=7 |pages=e101320|doi=10.1371/journal.pone.0101320 |pmid=25051345|pmc=4106761|bibcode=2014PLoSO...9j1320D|doi-access=free}} summarizing the evidence found no superior position for young, healthy males. For elderly males with LUTS, however, the sitting position when compared to the standing position is differentiated by the following:

• the post void residual volume (PVR, ml) was significantly decreased
• the maximum urinary flow (Qmax, ml/s) was increased
• the voiding time (VT, s) was decreased

This urodynamic profile is related to a lower risk of urologic complications, such as cystitis and bladder stones.

{{Main|Human sexual response cycle|Sexual arousal}}

The penis incites sexual arousal when sexually stimulated, such as from mental stimuli (sexual fantasy), partnered activity, or masturbation, which can lead to orgasm.

The glans and the frenulum are erogenous zones of the penis.{{cite book|last1=Crooks|first1=Robert|last2=Baur|first2=Karla|publisher=Thomson/Wadsworth|year=2008|title=Our Sexuality|page=90|isbn=978-0-49510-326-4|url=https://books.google.com/books?id=BoTZEAAAQBAJ&pg=PA57|access-date=2024-02-24|archive-date=2024-02-24|archive-url=https://web.archive.org/web/20240224000325/https://books.google.com/books?id=BoTZEAAAQBAJ&pg=PA90id=JXJGDwAAQBAJ&pg=PA57|url-status=live}} The glans has many nerve endings, which makes it the most sensitive.{{Cite book |last1=Olausson |first1=Håkan |title=Affective Touch and the Neurophysiology of CT Afferents |last2=Wessberg |first2=Johan |last3=Morrison |first3=India |publisher=Springer Science+Business Media |year=2016 |isbn=978-1-4939-6418-5 |pages=305 |quote=...the most pleasurable of all body parts when stimulated sexually: the glans (or tip) of the penis.}}{{medrs|date=November 2024|reason=WP:MEDDATE}} The most effective way to stimulate the penis is through oral stimulation (fellatio), manual stimulation (a handjob or manual masturbation), or during sexual penetration. Frot is mutual penile stimulation between men.

{{Main|Erection}}

File:Erection Development V2.jpg.|260x260px]]

File:Ventral and Dorsal View of Penis.jpg

An erection is the stiffening and rising of the penis, which occurs during sexual arousal, though it can also happen in non-sexual situations. Spontaneous erections frequently occur during adolescence due to friction with clothing, a full bladder or large intestine, hormone fluctuations, nervousness, and undressing in a nonsexual situation. It is also normal for erections to occur during sleep and upon waking. (See nocturnal penile tumescence.) The primary physiological mechanism that brings about erection is the autonomic dilation of arteries supplying blood to the penis, which allows more blood to fill the three spongy erectile tissue chambers in the penis, the corpora cavernosa and corpus spongiosum, causing it to lengthen and stiffen. After vasocongestion, the now-engorged erectile tissue presses against and constricts the veins that carry blood away from the penis. More blood enters than leaves the penis until an equilibrium is reached where an equal volume of blood flows into the dilated arteries and out of the constricted veins; a constant erectile size is achieved at this equilibrium.

Erection facilitates sexual intercourse though it is not essential for various other sexual activities.

Although many erect penises point upwards, it is common and normal for erect penis to curve in any direction. Many penises are curved in right, left, upwards or downwards direction depending upon the tension of the suspensory ligament that holds it in position.

The following table shows how common various erection angles are for a standing male, out of a sample of 81 males aged 21 through 67. In the table, zero degrees is pointing straight up against the abdomen, 90 degrees is horizontal and pointing straight forward, while 180 degrees would be pointing straight down to the feet. An upward pointing angle is most common.{{Cite journal|author=Sparling J |title=Penile erections: shape, angle, and length |journal=Journal of Sex & Marital Therapy |volume=23 |issue=3 |pages=195–207 |year=1997 |pmid=9292834 |doi=10.1080/00926239708403924}}{{medrs|date=November 2024|reason=WP:MEDDATE}}

{{Main article|Ejaculation}}

{{further|Orgasm#Males}}

Ejaculation is the ejection of semen from the penis. It is usually accompanied by orgasm. A series of muscular contractions delivers semen, containing male gametes known as sperm cells or spermatozoa, from the penis. Ejaculation usually happens as the result of sexual stimulation, but it can be due to prostatic disease in rare cases. Ejaculation may occur spontaneously during sleep (known as a nocturnal emission). Anejaculation is the condition of being unable to ejaculate.

Sperm are produced in the testicles and stored in the attached epididymides. During ejaculation, sperm are propelled up the vasa deferentia, two ducts that pass over and behind the bladder. Fluids are added by the seminal vesicles and the vasa deferentia turn into the ejaculatory ducts, which join the urethra inside the prostate. The prostate, as well as the bulbourethral glands, add further secretions (including pre-ejaculate), and the semen is expelled through the penis.

Ejaculation has two phases: emission and ejaculation proper. The emission phase of the ejaculatory reflex is under control of the sympathetic nervous system, while the ejaculatory phase is under control of a spinal reflex at the level of the spinal nerves S2–4 via the pudendal nerve. A refractory period succeeds the ejaculation, and sexual stimulation precedes it.Carlson, Neil. (2013). Physiology of Behavior. Upper Saddle River, New Jersey: Pearson Education, Inc.

The ischiocavernosus muscle helps to stabilize the penis during erection by compressing the crus and slowing the return of blood through the veins. The bulbospongiosus muscle also contributes to erection along with the expulsion of urine and semen.

The human penis has been argued to have several evolutionary adaptations that maximise reproductive success and minimise sperm competition. Sperm competition is where the sperm of two males simultaneously occupy the reproductive tract of a female and they compete to fertilise the egg.{{Cite journal|last1=Bleske-Rechek|first1=A. L.|last2=Euler|first2=H. A.|last3=LeBlanc|first3=G. J.|last4=Shackelford|first4=T. K.|last5=Weekes-Shackelford|first5=V. A.|date=2002|title=Psychological adaptation to human sperm competition.|journal=Evolution and Human Behavior|doi=10.1016/S1090-5138(01)00090-3|volume=23|issue=2|pages=123–138|bibcode=2002EHumB..23..123S }} If sperm competition results in the rival male's sperm fertilising the egg, cuckoldry could occur. This is the process whereby males unwittingly invest their resources into offspring of another male and, evolutionarily speaking, should be avoided.{{Cite journal|last1=Ehrke|first1=A. D.|last2=Pham|first2=M. N.|last3=Shackelford|first3=T. K.|last4=Welling|first4=L. L. M.|date=2013|title=Oral sex, semen displacement, and sexual arousal: testing the ejaculate adjustment hypothesis.|journal=Evolutionary Psychology|volume=11|issue=5|pages=1130–9|doi=10.1177/147470491301100515 |pmid=24356208|pmc=10429105 }}

The most researched human penis adaptations are penis size and semen displacement.{{Cite journal|last1=Shackelford|first1=Todd K.|last2=Goetz|first2=Aaron T.|s2cid=6179167|date=2007-02-01|title=Adaptation to Sperm Competition in Humans|journal=Current Directions in Psychological Science|volume=16|issue=1|pages=47–50|doi=10.1111/j.1467-8721.2007.00473.x|issn=0963-7214}}

Evolution has caused sexually selected adaptations to occur in penis size in order to maximise reproductive success and minimise sperm competition.{{Cite journal|last=Moller|first=A. P.|date=1988|title=Ejaculate quality, testes size and sperm competition in primates|journal=Journal of Human Evolution |volume=17 |issue= 5|pages= 479–488|doi=10.1016/0047-2484(88)90037-1|bibcode=1988JHumE..17..479M }}{{medrs|date=November 2024|reason=WP:MEDDATE}}{{Cite journal |last1=Mautz|first1=B. S.|last2=Wong|first2=B. B. M.|last3=Peters|first3=R. A.|last4=Jennions|first4=M. D. |date=April 23, 2013|title=Penis size interacts with body shape and height to influence male attractiveness |jstor=42590540 |journal=Proceedings of the National Academy of Sciences of the United States of America |volume=110 |issue=17 |pages=6925–30 |doi=10.1073/pnas.1219361110 |pmid=23569234 |pmc=3637716|bibcode=2013PNAS..110.6925M|doi-access=free}}{{medrs|date=November 2024|reason=WP:MEDDATE}}

Sperm competition has caused the human penis to evolve in length and size for sperm retention and displacement. To achieve this, the penis must be of sufficient length to reach any rival sperm and to maximally fill the vagina. In order to ensure that the female retains the male's sperm, the adaptations in length of the human penis have occurred so that the ejaculate is placed close to the female cervix.{{Cite book|title=Human Sexual Response|url=https://archive.org/details/humansexualrespo00will|url-access=registration|last1=Masters, W. H. |last2=Johnson, V. E.|publisher=Little, Brown and Company|year=1966|location=Boston|isbn=9780316549875}}{{medrs|date=November 2024|reason=WP:MEDDATE}} This is achieved when complete penetration occurs and the penis pushes against the cervix.{{Cite journal |last1=Schultz|first1=W. W.|last2=van Andel|first2=P.|last3=Sabelis|first3=I.|last4=Mooyaart|first4=E. |date=December 18, 1999|title=Magnetic resonance imaging of male and female genitals during coitus and female sexual arousal|url= |journal=BMJ |volume=319 |issue=7225|pages=1596–600 |doi=10.1136/bmj.319.7225.1596 |pmid=10600954|pmc=28302}}{{medrs|date=November 2024|reason=WP:MEDDATE, WP:MEDPRI}} These adaptations have occurred in order to release and retain sperm to the highest point of the vaginal tract. As a result, this adaptation also leaves the sperm less vulnerable to sperm displacement and semen loss. Another reason for this adaptation is that, due to the nature of the human posture, gravity creates vulnerability for semen loss. Therefore, a long penis, which places the ejaculate deep in the vaginal tract, could reduce the loss of semen.{{Cite journal |last1=Gallup|first1=G. G.|last2=Burch|first2=R. L. |date=January 1, 2004|title=Semen displacement as a sperm competition strategy in humans |journal=Evolutionary Psychology|doi=10.1177/147470490400200105 |volume=2|pages=147470490400200|doi-access=free}}{{medrs|date=November 2024|reason=WP:MEDDATE}}

Another evolutionary theory of penis size is female mate choice and its associations with social judgements in modern-day society.{{Cite journal |last1=Lever|first1=J.|last2=Frederick|first2=D. A.|last3=Peplau|first3=L. A.|date=2006|title=Does size matter? Men's and women's views on penis size across the lifespan|journal=Psychology of Men and Masculinity |volume=7 |issue= 3|pages= 129–143|doi=10.1037/1524-9220.7.3.129}}{{medrs|date=November 2024|reason=WP:MEDDATE}} A study which illustrates female mate choice as an influence on penis size presented females with life-size, rotatable, computer generated males. These varied in height, body shape and flaccid penis size, with these aspects being examples of masculinity.{{medrs|date=November 2024|reason=WP:MEDDATE}} Female ratings of attractiveness for each male revealed that larger penises were associated with higher attractiveness ratings.{{medrs|date=November 2024|reason=WP:MEDDATE}} These relations between penis size and attractiveness have therefore led to frequently emphasized associations between masculinity and penis size in popular media.{{medrs|date=November 2024|reason=WP:MEDDATE}} This has led to a social bias existing around penis size with larger penises being preferred and having higher social status. This is reflected in the association between believed sexual prowess and penis size and the social judgement of penis size in relation to 'manhood'.{{medrs|date=November 2024|reason=WP:MEDDATE}}

The shape of the human penis is thought to have evolved as a result of sperm competition.{{Cite journal|title = Adaptation to Sperm Competition in Humans|journal = Current Directions in Psychological Science|date = 2007-02-01|issn = 0963-7214|pages = 47–50|volume = 16|issue = 1|doi = 10.1111/j.1467-8721.2007.00473.x|first1 = Todd K.|last1 = Shackelford|first2 = Aaron T.|last2 = Goetz|s2cid = 6179167}} Semen displacement is an adaptation of the shape of the penis to draw foreign semen away from the cervix. This means that in the event of a rival male's sperm occupying the reproductive tract of a female, the human penis is able to displace the rival sperm, replacing it with his own.

Semen displacement has two main benefits for a male. Firstly, by displacing a rival male's sperm, the risk of the rival sperm fertilising the egg is reduced.{{cite journal|last1=Burch|first1=R. L.|last2=Gallup|first2=G. G.|last3=Parvez|first3=R. A.|last4=Stockwell|first4=M. L.|last5=Zappieri|first5=M. L.|title=The human penis as a semen displacement device.|journal=Evolution and Behaviour|date=2003|volume=24|issue=4|pages=277–289|doi=10.1016/S1090-5138(03)00016-3|bibcode=2003EHumB..24..277G }} Secondly, the male replaces the rival's sperm with his own, thereby increasing the probability of his fertilising the egg and successfully reproducing with the female. However, males have to ensure they do not displace their own sperm. It is thought that the relatively quick loss of erection after ejaculation, penile hypersensitivity following ejaculation, and the shallower, slower thrusting of the male after ejaculation prevent this from occurring.{{cite journal|last2=Gallup|first2=G. G.|last3=Mitchell|first3=T. J.|date=2006|title=Semen displacement as a sperm competition strategy: Multiple mating, self-semen displacement, and timing of in-pair copulations|journal=Human Nature |volume=17|issue=3|pages=253–264|last1=Burch|first1=R. L.|s2cid=31703430|doi=10.1007/s12110-006-1008-9 |pmid=26181472}}

The coronal ridge is the part of the human penis thought to have evolved to allow for semen displacement. Research has studied how much semen is displaced by differently shaped artificial genitals. This research showed that, when combined with thrusting, the coronal ridge of the penis is able to remove the seminal fluid of a rival male from within the female reproductive tract. It does this by forcing the semen under the frenulum of the coronal ridge, causing it to collect behind the coronal ridge shaft. When model penises without a coronal ridge were used, less than half the artificial sperm was displaced, compared to penises with a coronal ridge.

The presence of a coronal ridge alone, however, is not sufficient for effective semen displacement. It must be combined with adequate thrusting to be successful. It has been shown that the deeper the thrusting, the larger the semen displacement. No semen displacement occurs with shallow thrusting. Some have therefore termed thrusting as a semen displacement behaviour.{{Cite journal |last1=Euler|first1=H. A.|last2=Goetz|first2=A. T.|last3=Hoier|first3=S.|last4=Shackelford|first4=T. K.|last5=Weekes-Shackelford|first5=V. A.|date=2005|title=Mate retention, semen displacement, and human sperm competition: A preliminary investigation of tactics to prevent and correct female infidelity.|journal=Personality and Individual Differences|doi=10.1016/j.paid.2004.05.028|volume=38|issue=4|pages=749–763}}

The behaviours associated with semen displacement, namely thrusting (number of thrusts and depth of thrusts), and duration of sexual intercourse, have been shown to vary according to whether a male perceives the risk of partner infidelity to be high or not. Males and females report greater semen displacement behaviours following allegations of infidelity. In particular, following allegations of infidelity, males and females report deeper and quicker thrusting during sexual intercourse.

• Paraphimosis is an inability to move the foreskin forward over the glans. It can result from fluid trapped in a foreskin left retracted, perhaps following a medical procedure, or accumulation of fluid in the foreskin because of friction during vigorous sexual activity.
• In Peyronie's disease, anomalous scar tissue grows in the soft tissue of the penis, causing curvature. Severe cases can be improved by surgical correction.
• A thrombosis can occur during periods of frequent and prolonged sexual activity, especially fellatio. It is usually harmless and self-corrects within a few weeks.
• Sexually transmitted infections, for example, herpes virus, which can occur after sexual contact with an infected carrier; this may lead to the development of herpes sores.
• Balanitis is an inflammation, either infectious or not.
• Pudendal nerve entrapment is a condition characterized by pain on sitting and the loss of penile sensation and orgasm. Occasionally, there is a total loss of sensation and orgasm. The pudendal nerve can be damaged by narrow, hard bicycle seats and accidents.
• Penile fracture can occur if the erect penis is bent excessively. A popping or cracking sound and pain is normally associated with this event. Emergency medical assistance should be obtained as soon as possible. Prompt medical attention lowers the likelihood of permanent penile curvature.
• In diabetes, peripheral neuropathy can cause tingling in the penile skin and possibly reduced or completely absent sensation. The reduced sensations can lead to injuries for either partner and their absence can make it impossible to have sexual pleasure through stimulation of the penis. Since the problems are caused by permanent nerve damage, preventive treatment through good control of the diabetes is the primary treatment. Some limited recovery may be possible through improved diabetes control.
• Erectile dysfunction is the inability to develop and maintain an erection sufficiently firm for satisfactory sexual performance. Diabetes is a leading cause, as is natural aging. A variety of treatments exist, most notably including the phosphodiesterase type 5 inhibitor drugs (such as sildenafil citrate, marketed as Viagra), which work by vasodilation.
• Priapism, a form of persistent genital arousal disorder, is a painful and potentially harmful medical condition in which the erect penis does not return to its flaccid state. Priapism lasting over four hours is a medical emergency. The causative mechanisms are poorly understood but involve complex neurological and vascular factors. Potential complications include ischaemia, thrombosis, and impotence. In serious cases the condition may result in gangrene, which may result in amputation. However, that is usually only the case if the organ is broke out and injured because of it. The condition has been associated with a variety of drugs including prostaglandin. Contrary to common knowledge, sildenafil (Viagra) will not cause it.{{Cite journal|author=Goldenberg MM |title=Safety and efficacy of sildenafil citrate in the treatment of male erectile dysfunction |journal=Clinical Therapeutics |volume=20 |issue=6 |pages=1033–48 |year=1998 |pmid=9916601 |doi=10.1016/S0149-2918(98)80103-3|doi-access=free }}
• Lymphangiosclerosis is a hardened lymph vessel, although it can feel like a hardened, almost calcified or fibrous, vein. It tends not to share the common blue tint with a vein however. It can be felt as a hardened lump or "vein" even when the penis is flaccid, and is even more prominent during an erection. It is considered a benign physical condition. It is fairly common and can follow a particularly vigorous sexual activity for men, and tends to go away if given rest and more gentle care, for example by use of lubricants.
• Carcinoma of the penis is rare with a reported rate of 1 person in 100,000 in developed countries. Some sources state that circumcision can protect against this disease, but this notion remains controversial among medical circles.{{Cite journal|vauthors=Boczko S, Freed S |title=Penile carcinoma in circumcised males |journal=New York State Journal of Medicine |volume=79 |issue=12 |pages=1903–4 |date=November 1979 |pmid=292845}}
• Hard flaccid syndrome is a rare, chronic condition characterized by a flaccid penis that remains in a firm, semi-rigid state in the absence of sexual arousal.
• Cold glans syndrome is a condition marked by the persistent inability of the glans penis to maintain an erect state during sexual arousal, potentially leading to reduced sensitivity and erection difficulties.

• Hypospadias is a developmental disorder where the meatus is positioned wrongly at birth. Hypospadias can also occur iatrogenically by the downward pressure of an indwelling urethral catheter.{{Cite journal|vauthors=Andrews HO, Nauth-Misir R, Shah PJ |title=Iatrogenic hypospadias—a preventable injury? |journal=Spinal Cord |volume=36 |issue=3 |pages=177–80 |date=March 1998 |pmid=9554017 |doi=10.1038/sj.sc.3100508|doi-access=free }} It is usually corrected by surgery.
• A micropenis is a very small penis caused by developmental or congenital problems.
• Diphallia, or penile duplication (PD), is the rare condition of having two penises.

• Penis panic (koro in Malaysian/Indonesian) — delusion of shrinkage of the penis and retraction into the body. This appears to be culturally conditioned and largely limited to Ghana, Sudan, China, Japan, Southeast Asia, and West Africa.
• In April 2008, Kinshasa, Democratic Republic of Congo, the West African police arrested 14 suspected victims (of penis snatching) and sorcerers accused of using black magic or witchcraft to steal (make disappear) or shrink men's penises to extort cash for cure, amid a wave of panic. Arrests were made in an effort to avoid bloodshed seen in Ghana a decade before, when 12 penis snatchers were beaten to death by mobs.{{cite news|url=https://www.reuters.com/article/us-congo-democratic-witchcraft-idUSL2290323220080422|title=Lynchings in Congo as penis theft panic hits capital|date=22 April 2017|access-date=16 January 2017|newspaper=Reuters|archive-date=7 December 2022|archive-url=https://web.archive.org/web/20221207011537/https://www.reuters.com/article/us-congo-democratic-witchcraft-idUSL2290323220080422|url-status=live}}
• Penis envy — the contested Freudian belief of all women inherently envying men for having penises.

File:Elizabeth Float Kanamara Festival 2007.JPG festival in Japan]]

File:Male Genital Piercing.jpg piercing wearing captive bead ring jewelry]]

File:Dani Mann Baliem-Tal.jpg man wearing traditional penis sheath]]

In many cultures, referring to the penis is considered taboo or vulgar, and a variety of slang words and euphemisms are used to talk about it. In English, these include member, dick, cock, prick, johnson, dork, peter, pecker, manhood, stick, rod, third/middle leg, dong, willy, schlong, and todger.{{cite web|url=http://www.collinsdictionary.com/dictionary/english/todger|title=todger - Definition, meaning & more - Collins Dictionary|access-date=16 January 2017|archive-date=7 August 2016|archive-url=https://web.archive.org/web/20160807031236/http://www.collinsdictionary.com/dictionary/english/todger|url-status=live}} Many of these are used as insults—though sometimes playfully—meaning an unpleasant or unworthy person.Marv Rubinstein, American English Compendium: A Portable Guide to the Idiosyncrasies, Subtleties, Technical Lingo, and Nooks and Crannies of American English, {{ISBN|1442232838}}, p. 147Ruth Bell, Changing Bodies, Changing Lives: Expanded Third Edition: A Book for Teens on Sex and Relationships, {{ISBN|0307794067}}, p. 15 Among these, historically, the most commonly used euphemism for penis in English literature and society was member.{{cite book|author=David M. Friedman|title=A Mind of Its Own: A Cultural History of the Penis|date=4 September 2008|publisher=Simon and Schuster|isbn=978-1-43-913608-9|page=43}}

{{Main|Genital modification and mutilation}}

The penis is sometimes pierced or decorated by other body art. Other than circumcision, genital alterations are almost universally elective and usually for the purpose of aesthetics or increased sensitivity. Piercings of the penis include the Prince Albert, apadravya, ampallang, dydoe, deep shaft and frenum piercings. Foreskin restoration or stretching is a further form of body modification, as well as implants under the shaft of the penis. Another type of alteration to the penis is genital tattooing.

Trans women who undergo sex reassignment surgery have their penis surgically modified into a vagina or clitoris via vaginoplasty or clitoroplasty respectively.{{cite book|last=Koch|first=Anne L.|title=It Never Goes Away: Gender Transition at a Mature Age|publisher=Rutgers University Press|year=2019|page=89|url=https://books.google.com/books?id=BXCCEAAAQBAJ&pg=PA89|isbn=978-0-81359-839-0}} Trans men who undergo such surgery have a phalloplasty or metoidioplasty.

Other practices that alter the penis are also performed, although they are rare in Western societies without a diagnosed medical condition. Apart from penectomy, perhaps the most radical of these is subincision, in which the urethra is split along the underside of the penis. Subincision originated among Australian Aborigines, although it is now done by some in the U.S. and Europe.

{{Main|Circumcision}}

File:Circumcised penis labelled.jpg; (2) circumcision scar; (3) corona; (4) glans; and (5) meatus]]

The most common form of body modification related to the penis is circumcision: removal of part or all of the foreskin. It is most commonly performed as an elective procedure for prophylactic, cultural, or religious reasons.{{Cite book |last1=Alan Glasper |first1=Edward |title=A Textbook of Children's and Young People's Nursing |last2=Richardson |first2=James |last3=Randall |first3=Duncan |publisher=Elsevier Health Sciences |year=2021 |isbn=9780702065033 |pages=382 |chapter=Promote, Restore, and Stabilise Health Status in Children}} For infant circumcision, modern devices such as the Gomco clamp, Plastibell, and Mogen clamp are available.{{Cite journal |vauthors=Holman JR, Lewis EL, Ringler RL |title=Neonatal circumcision techniques |journal=American Family Physician |volume=52 |issue=2 |pages=511–520 |date=August 1995 |pmid=7625325}} The ethics of circumcision in children is a source of controversy.{{cite web|url=http://www.racp.edu.au/download.cfm?DownloadFile=A453CFA1-2A57-5487-DF36DF59A1BAF527|title=Policy Statement On Circumcision|access-date=2007-02-28|date=September 2004|format=PDF|publisher=Royal Australasian College of Physicians|quote=The Paediatrics and Child Health Division, The Royal Australasian College of Physicians (RACP) has prepared this statement on routine circumcision of infants and boys to assist parents who are considering having this procedure undertaken on their male children and for doctors who are asked to advise on or undertake it. After extensive review of the literature the RACP reaffirms that there is no medical indication for routine neonatal circumcision. Circumcision of males has been undertaken for religious and cultural reasons for many thousands of years. It remains an important ritual in some religious and cultural groups.…In recent years there has been evidence of possible health benefits from routine male circumcision. The most important conditions where some benefit may result from circumcision are urinary tract infections, HIV and later cancer of the penis.…The complication rate of neonatal circumcision is reported to be around 1% and includes tenderness, bleeding and unhappy results to the appearance of the penis. Serious complications such as bleeding, septicaemia and may occasionally cause death (1 in 550,000). The possibility that routine circumcision may contravene human rights has been raised because circumcision is performed on a minor and is without proven medical benefit. Whether these legal concerns are valid will be known only if the matter is determined in a court of law. If the operation is to be performed, the medical attendant should ensure this is done by a competent operator, using appropriate anaesthesia and in a safe child-friendly environment. In all cases where parents request a circumcision for their child the medical attendant is obliged to provide accurate information on the risks and benefits of the procedure. Up-to-date, unbiased written material summarizing the evidence should be widely available to parents. Review of the literature in relation to risks and benefits shows there is no evidence of benefit outweighing harm for circumcision as a routine procedure in the neonate. |archive-url = https://web.archive.org/web/20080720092409/http://www.racp.edu.au/download.cfm?DownloadFile=A453CFA1-2A57-5487-DF36DF59A1BAF527 |archive-date = 2008-07-20}}{{cite web| url = http://www.bma.org.uk/ap.nsf/Content/malecircumcision2006?OpenDocument&Highlight=2,circumcision| title = The law and ethics of male circumcision - guidance for doctors| access-date = 2006-07-01| author = Medical Ethics Committee|date=June 2006| publisher = British Medical Association|archive-url = https://web.archive.org/web/20071112055050/http://www.bma.org.uk/ap.nsf/Content/malecircumcision2006?OpenDocument&Highlight=2,circumcision |archive-date = 2007-11-12}} Among the world's major medical organizations, there is a consensus that circumcision reduces heterosexual HIV infection rates in high-risk populations during penile-vaginal sex.{{Cite report

| title = New Data on Male Circumcision and HIV Prevention: Policy and Programme Implications

| publisher = World Health Organization

| date = March 28, 2007

| url = https://www.who.int/hiv/mediacentre/MCrecommendations_en.pdf

| access-date = 2007-08-13

| archive-date = 2020-03-02

| archive-url = https://web.archive.org/web/20200302152109/http://www.who.int/hiv/mediacentre/MCrecommendations_en.pdf

| url-status = live

}}{{cite web |title=Male Circumcision and Risk for HIV Transmission and Other Health Conditions: Implications for the United States |publisher=Centers for Disease Control and Prevention |year=2008 |url=https://stacks.cdc.gov/view/cdc/13545 |access-date=2013-11-07 |archive-date=2017-02-20 |archive-url=https://web.archive.org/web/20170220012538/https://stacks.cdc.gov/view/cdc/13545 |url-status=live }}{{Cite journal |last1=Chikutsa |first1=Antony |last2=Maharaj |first2=Pranitha |date=July 2015 |title=Social representations of male circumcision as prophylaxis against HIV/AIDS in Zimbabwe |journal=BMC Public Health |language=en |volume=15 |issue=1 |pages=603 |doi=10.1186/s12889-015-1967-z |issn=1471-2458 |pmc=4489047 |pmid=26133368 |quote=It is now generally accepted in public health spheres that medical male circumcision is efficacious in the prevention of HIV infection. |doi-access=free }}{{Cite book |last1=Merson |first1=Michael |title=The AIDS Pandemic: Searching for a Global Response |last2=Inrig |first2=Stephen |publisher=Springer Publishing |year=2017 |isbn=9783319471334 |pages=379 |quote=This led to a [medical] consensus that male circumcision should be a priority for HIV prevention in countries and regions with heterosexual epidemics and high HIV and low male circumcision prevalence.}} There are differing perspectives on the prophylactic efficacy and cost effectiveness of circumcision in developed nations. Circumcision plays a significant role in many of the world's cultures.{{Cite book |last=Benson |first=Janette |title=Encyclopedia of Infant and Early Childhood Development: A-F |publisher=Academic Press |year=2008 |isbn=9780123704610 |pages=279}} When performed for religious reasons, it is most common among both Jews and Muslims, among whom it is near-universal.{{cite book|title=The Druze and Their Faith in Tawhid| first=Anis|last=Ubayd|year= 2006| isbn=9780815630975| page =150|publisher=Syracuse University Press|quote=Male circumcision is standard practice, by tradition, among the Druze}}

There are efforts by scientists to partially or fully regenerate the structures of the human penis.{{Cite journal|last1=Patel|first1=Manish|last2=Atala|first2=Anthony |author-link2=Anthony Atala|date=2011-12-29|title=Tissue Engineering of the Penis|journal=The Scientific World Journal|volume=11|pages=2567–2578|doi=10.1100/2011/323989|issn=2356-6140|pmc=3253692|pmid=22235188 |doi-access=free }}{{Cite journal|last1=Andrew|first1=Tom W.|last2=Kanapathy|first2=Muholan|last3=Murugesan|first3=Log|last4=Muneer|first4=Asif|last5=Kalaskar|first5=Deepak|last6=Atala|first6=Anthony|date=October 24, 2019|title=Towards clinical application of tissue engineering for erectile penile regeneration|url=https://www.nature.com/articles/s41585-019-0246-7|journal=Nature Reviews Urology|volume=16|issue=12|pages=734–744|doi=10.1038/s41585-019-0246-7|pmid=31649327|s2cid=204883088|issn=1759-4820|access-date=November 19, 2020|archive-date=July 19, 2022|archive-url=https://web.archive.org/web/20220719100813/https://www.nature.com/articles/s41585-019-0246-7|url-status=live}}{{Cite journal|last1=Pozzi|first1=Edoardo|last2=Muneer|first2=Asif|last3=Sangster|first3=Pippa|last4=Alnajjar|first4=Hussain M.|last5=Salonia|first5=Andrea|last6=Bettocchi|first6=Carlo|last7=Castiglione|first7=Fabio|last8=Ralph|first8=David J.|date=July 2019|title=Stem-cell regenerative medicine as applied to the penis|url=https://dx.doi.org/10.1097%2FMOU.0000000000000636|journal=Current Opinion in Urology|volume=29|issue=4|pages=443–449|doi=10.1097/MOU.0000000000000636|pmid=31008782|s2cid=128353913|issn=0963-0643|access-date=2020-11-21|archive-date=2024-03-18|archive-url=https://web.archive.org/web/20240318205444/https://journals.lww.com/co-urology/abstract/2019/07000/stem_cell_regenerative_medicine_as_applied_to_the.22.aspx|url-status=live}} Patients who can benefit most from this field are those who have congenital defects, cancer, and injuries that have excised parts of their genitalia.{{Cite book |last1=Moore |first1=Lisa |title=The Body: Social and Cultural Dissections |last2=Casper |first2=Monica |publisher=Taylor & Francis |year=2014 |isbn=9781136771798 |pages=74}} Some organizations which perform research into, or conduct regeneration procedures, include the Wake Forest Institute for Regenerative Medicine and the United States Department of Defense.{{Cite journal|last1=Ude|first1=Chinedu Cletus|last2=Miskon|first2=Azizi |last3=Idrus|first3=Ruszymah Bt Hj |last4=Abu Bakar|first4=Muhamad Bin|date=2018-02-26|title=Application of stem cells in tissue engineering for defense medicine|url= |journal=Military Medical Research|volume=5 |issue=1|pages=7|doi=10.1186/s40779-018-0154-9 |issn=2054-9369|pmc=6389246|pmid=29502528 |doi-access=free }}{{Cite web|last=Ferreira|first=Becky|date=October 6, 2014|title=How to Grow An Artificial Penis|url=https://www.vice.com/en/article/how-to-grow-an-artificial-penis/|access-date=November 19, 2020|website=Vice News|language=en|archive-date=November 11, 2020|archive-url=https://web.archive.org/web/20201111215409/https://www.vice.com/en/article/z4mqnj/how-to-grow-an-artificial-penis|url-status=live}} The first successful penis allotransplant surgery was done in September 2005 in a military hospital in Guangzhou, China.{{cite web|title=世界首例异体阴茎移植成功 40岁患者数周后出院·广东新闻·珠江三角洲·南方新闻网|url=http://www.southcn.com/news/gdnews/nanyuetuijian/200509220074.htm|access-date=16 January 2017|archive-date=3 March 2016|archive-url=https://web.archive.org/web/20160303234128/http://www.southcn.com/news/gdnews/nanyuetuijian/200509220074.htm|url-status=live}} A man at 44 sustained an injury after an accident and his penis was severed; urination became difficult as his urethra was partly blocked. A recently brain-dead man, aged 23, was selected for the transplant. Despite atrophy of blood vessels and nerves, the arteries, veins, nerves and the corpora spongiosa were successfully matched. But, on 19 September (after two weeks), the surgery was reversed because of a severe psychological problem (rejection) by the recipient and his wife.{{Cite news|last=Sample|first=Ian|date=2006-09-18|title=Man rejects first penis transplant|work=The Guardian|location=London|url=https://www.theguardian.com/science/2006/sep/18/medicineandhealth.china|access-date=2010-05-22|archive-date=2018-05-31|archive-url=https://web.archive.org/web/20180531191928/https://www.theguardian.com/science/2006/sep/18/medicineandhealth.china|url-status=live}}

In 2009, researchers Chen, Eberli, Yoo and Atala have produced bioengineered penises and implanted them on rabbits.{{Cite journal|vauthors=Chen KL, Eberli D, Yoo JJ, Atala A|date=November 2009 |title=Regenerative Medicine Special Feature: Bioengineered corporal tissue for structural and functional restoration of the penis|journal=Proceedings of the National Academy of Sciences of the United States of America|volume=107 |issue=8|pages=3346–50|bibcode=2010PNAS..107.3346C|doi=10.1073/pnas.0909367106|pmc=2840474|pmid=19915140|doi-access=free}} They were able to obtain erection and copulate, with 10 of 12 rabbits achieving ejaculation. This study shows that in the future it could be possible to produce artificial penises for replacement surgeries or phalloplasties. In 2015, the world's first successful penis transplant took place in Cape Town, South Africa in a nine-hour operation performed by surgeons from Stellenbosch University and Tygerberg Hospital. The 21-year-old recipient, who had been sexually active, had lost his penis in a botched circumcision at 18.{{cite news|last=Gallagher|first=James|date=13 March 2015|title=South Africans perform first 'successful' penis transplant|work=BBC News|url=https://www.bbc.com/news/health-31876219|access-date=16 January 2017|archive-date=17 March 2019|archive-url=https://web.archive.org/web/20190317173847/https://www.bbc.com/news/health-31876219|url-status=live}}

• Buried penis
• Castration anxiety
• Dick joke
• Dildo
• Genital ulcer
• Crotch (in clothing) – a pouch-shaped area built to accommodate a penis and scrotum
• Penile enlargement
• Penis removal
• Phallic architecture
• Phallus – an object or image that resembles a penis
• Preputioplasty – an operation performed to facilitate retraction of the foreskin
• Stunt cock – a substitute penis used for filmmaking
• Vulva – the external, visible structures of the human female genitalia

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Category:Human anatomy

Category:Human male reproductive system

Category:Mammal male reproductive system

Category:Men's health

Category:Penis

Category:Urinary system

Category:Sex organs