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[[File:Penis .jpg|thumb|left|A circumcised penis, semi-erect.]] |
[[File:Penis .jpg|thumb|left|A circumcised penis, semi-erect.]] |
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The most common form of genital alteration is [[circumcision]]: removal of part or all of the foreskin for various cultural, religious, and more rarely medical reasons. For infant circumcision, modern devices such as the [[Gomco clamp]], [[Plastibell]], and Mogen clamp are available.<ref>{{cite journal |
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Adult circumcisions are often performed without clamps and require 4 to 6 weeks of abstinence from [[masturbation]] or intercourse after the operation to allow the wound to heal.<ref>{{cite journal |last=Holman |first=J.R. |authorlink= |coauthors=K.A. Stuessi |year=1999 |month=March |title=Adult circumcision |journal=American Family Physician |volume=59 |issue=6 |pages=1514–1518 |pmid=10193593 |url=http://www.aafp.org/afp/990315ap/1514.html |accessdate= |quote= }}</ref> In some African countries, male circumcision is often performed by non-medical personnel under unsterile conditions.<ref>{{cite web |url=http://www.iht.com/articles/2007/02/27/news/health.php |title=In Africa, a problem with circumcision and AIDS}}</ref> After hospital circumcision, the foreskin may be used in biomedical research,<ref>{{cite journal |last=Hovatta |first=O. |coauthors=M. Mikkola1, K. Gertow, A.-M. Strömberg, J. Inzunza1, J. Hreinsson1, B. Rozell, E. Elisabeth Blennow, M. Andäng, L. Ährlund-Richter |year=2003 |month=July |title=A culture system using human foreskin fibroblasts as feeder cells allows production of human embryonic stem cells |journal=Human Reproduction |volume=18 |issue=7 |pages=1404–1409 |pmid=12832363 |url= |doi=10.1093/humrep/deg290 }}</ref> consumer skin-care products,<ref>{{cite web |url=http://www.nbc10.com/health/1808693/detail.html |title=The Skinny On 'Miracle' Wrinkle Cream|year=2002|month=November|publisher=NBC Universal, Inc|work=NBC10.com|accessdate=2008-08-20}}</ref> skin grafts,<ref>{{cite web|url=http://www.wired.com/science/discoveries/news/1999/02/17912|title=High-Tech Skinny on Skin Grafts|date=02.16.99|publisher=CondéNet, Inc|work=www.wired.com:science:discoveries|accessdate=2008-08-20}}</ref><ref>{{cite web|url=http://www.emedicine.com/derm/TOPIC867.HTM|title=Skin Grafting|publisher=WebMD|work=www.emedicine.com|accessdate=2008-08-20}}</ref><ref>{{cite web|first=Catherine|last=Amst|coauthors=Carey, John|url=http://www.businessweek.com/1998/30/b3588001.htm|title=Biotech Bodies|date=July 27, 1998|publisher=The McGraw-Hill Companies Inc|work=www.businessweek.com|accessdate=2008-08-20}}</ref> or [[interferon|β-interferon]]-based drugs.<ref>{{cite web |author=Cowan, Alison Leigh|url=http://query.nytimes.com/gst/fullpage.html?res=9E0CE6D81E38F93AA25757C0A964958260&partner |title=Wall Street; A Swiss Firm Makes Babies Its Bet|date=April 19, 1992|publisher=New York Times|work=New York Times:Business|accessdate=2008-08-20}}</ref> In parts of Africa, the foreskin may be dipped in brandy and eaten by the patient, eaten by the circumciser, or fed to animals.<ref>{{cite journal | last = Anonymous (editorial)| title = A ritual operation| journal = British Medical Journal| volume = 2| pages = 1458–1459| date = 1949-12-24| pmc = 2051965 |quote=<small>"...in parts of West Africa, where the operation is performed at about 8 years of age, the prepuce is dipped in brandy and eaten by the patient; in other districts the operator is enjoined to consume the fruits of his handiwork, and yet a further practice, in Madagascar, is to wrap the operation specifically in a banana leaf and feed it to a calf."</small>| accessdate = 2008-09-26}}</ref> According to [[halakha|Jewish law]], after a ''[[Brit milah]]'', the foreskin should be buried.<ref>''[[Shulchan Aruch]]'', ''[[Yoreh Deah]]'', 265:10</ref> |
Adult circumcisions are often performed without clamps and require 4 to 6 weeks of abstinence from [[masturbation]] or intercourse after the operation to allow the wound to heal.<ref>{{cite journal |last=Holman |first=J.R. |authorlink= |coauthors=K.A. Stuessi |year=1999 |month=March |title=Adult circumcision |journal=American Family Physician |volume=59 |issue=6 |pages=1514–1518 |pmid=10193593 |url=http://www.aafp.org/afp/990315ap/1514.html |accessdate= |quote= }}</ref> In some African countries, male circumcision is often performed by non-medical personnel under unsterile conditions.<ref>{{cite web |url=http://www.iht.com/articles/2007/02/27/news/health.php |title=In Africa, a problem with circumcision and AIDS}}</ref> After hospital circumcision, the foreskin may be used in biomedical research,<ref>{{cite journal |last=Hovatta |first=O. |coauthors=M. Mikkola1, K. Gertow, A.-M. Strömberg, J. Inzunza1, J. Hreinsson1, B. Rozell, E. Elisabeth Blennow, M. Andäng, L. Ährlund-Richter |year=2003 |month=July |title=A culture system using human foreskin fibroblasts as feeder cells allows production of human embryonic stem cells |journal=Human Reproduction |volume=18 |issue=7 |pages=1404–1409 |pmid=12832363 |url= |doi=10.1093/humrep/deg290 }}</ref> consumer skin-care products,<ref>{{cite web |url=http://www.nbc10.com/health/1808693/detail.html |title=The Skinny On 'Miracle' Wrinkle Cream|year=2002|month=November|publisher=NBC Universal, Inc|work=NBC10.com|accessdate=2008-08-20}}</ref> skin grafts,<ref>{{cite web|url=http://www.wired.com/science/discoveries/news/1999/02/17912|title=High-Tech Skinny on Skin Grafts|date=02.16.99|publisher=CondéNet, Inc|work=www.wired.com:science:discoveries|accessdate=2008-08-20}}</ref><ref>{{cite web|url=http://www.emedicine.com/derm/TOPIC867.HTM|title=Skin Grafting|publisher=WebMD|work=www.emedicine.com|accessdate=2008-08-20}}</ref><ref>{{cite web|first=Catherine|last=Amst|coauthors=Carey, John|url=http://www.businessweek.com/1998/30/b3588001.htm|title=Biotech Bodies|date=July 27, 1998|publisher=The McGraw-Hill Companies Inc|work=www.businessweek.com|accessdate=2008-08-20}}</ref> or [[interferon|β-interferon]]-based drugs.<ref>{{cite web |author=Cowan, Alison Leigh|url=http://query.nytimes.com/gst/fullpage.html?res=9E0CE6D81E38F93AA25757C0A964958260&partner |title=Wall Street; A Swiss Firm Makes Babies Its Bet|date=April 19, 1992|publisher=New York Times|work=New York Times:Business|accessdate=2008-08-20}}</ref> In parts of Africa, the foreskin may be dipped in brandy and eaten by the patient, eaten by the circumciser, or fed to animals.<ref>{{cite journal | last = Anonymous (editorial)| title = A ritual operation| journal = British Medical Journal| volume = 2| pages = 1458–1459| date = 1949-12-24| pmc = 2051965 |quote=<small>"...in parts of West Africa, where the operation is performed at about 8 years of age, the prepuce is dipped in brandy and eaten by the patient; in other districts the operator is enjoined to consume the fruits of his handiwork, and yet a further practice, in Madagascar, is to wrap the operation specifically in a banana leaf and feed it to a calf."</small>| accessdate = 2008-09-26}}</ref> According to [[halakha|Jewish law]], after a ''[[Brit milah]]'', the foreskin should be buried.<ref>''[[Shulchan Aruch]]'', ''[[Yoreh Deah]]'', 265:10</ref> |
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A recent study<ref name="pmid17378847">{{cite journal |
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|author=Sorrells ML, Snyder JL, Reiss MD, ''et al.'' |title=Fine-touch pressure thresholds in the adult penis |journal=[[BJU International]] |volume=99 |issue=4 |pages=864–9 |year=2007 |month=April |pmid=17378847 |doi=10.1111/j.1464-410X.2006.06685.x |url=http://www.doctorsopposingcircumcision.org/pdf/sorrells_2007.pdf |issn= |
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}}</ref> comparing the penile sensitivity of intact and circumcised penises to fine-touch pressure shows the only statistically significant differences occur in the areas unique to each: namely, the foreskin and frenulum of intact men, and the scar area of circumcised men (see graph). The implications of this data for sexual pleasure and function are a matter of ongoing debate, with a large number of studies producing often contradictory results (see [[Sexual effects of circumcision]]). |
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There is controversy surrounding circumcision. [[Circumcision advocacy|Advocates of circumcision]] argue, for example, that it provides important health advantages which outweigh the risks, has no substantial effects on sexual function, has a low complication rate when carried out by an experienced physician, and is best performed during the neonatal period.<ref name="Schoen">{{cite journal |
There is controversy surrounding circumcision. [[Circumcision advocacy|Advocates of circumcision]] argue, for example, that it provides important health advantages which outweigh the risks, has no substantial effects on sexual function, has a low complication rate when carried out by an experienced physician, and is best performed during the neonatal period.<ref name="Schoen">{{cite journal |
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Revision as of 10:48, 23 January 2010
The penis (plural penises, penes) is an external sexual organ of certain biologically male organisms, in both vertebrates and invertebrates.
The penis is a reproductive organ, technically an intromittent organ, and for placental mammals, additionally serves as the external organ of urination. The penis is generally found on mammals and reptiles.
Linguistics
Etymology
The word "penis" is taken from the Latin word for "tail." Some derive that from Indo-European *pesnis, and the Greek word πεος = "penis" from Indo-European *pesos. Prior to the adoption of the Latin word in English the penis was referred to as a "yard". The Oxford English Dictionary cites an example of the word yard used in this sense from 1379,[1] and notes that in his Physical Dictionary of 1684, Steven Blankaart defined the word penis as "the Yard, made up of two nervous Bodies, the Channel, Nut, Skin, and Fore-skin, etc."[2]
The Latin word "phallus" (from Greek φαλλος) is sometimes used to describe the penis, although "phallus" originally was used to describe images, pictorial or carved, of the penis.[3]
The adjectival form of the word penis is penile. This adjective is commonly used in describing the male copulatory organ's various accessory structures which are commonly found in many kinds of invertebrate animals.
Slang
As with nearly any aspect of the human body that is involved in sexual or excretory functions, the word penis is considered funny from a juvenile perspective, and there are many slang words and euphemisms for the penis, such as "cock", "dick", "schlong", "johnson", "willy", or "pecker".
"Penii" is sometimes facetiously or mistakenly used as a plural form of "penis" instead of "penes" or "penises," its correct forms.
Humans
Parts
- Root of the penis(Radix):It is the attached part, consisting of Bulb of penis in the middle and Crus of penis one on either side of the bulb. It lies within the superficial perineal pouch.
- Body of the penis(Corpus):It has two surfaces dorsal(posterosuperior in erect penis)and ventral or urethral(facing downwards and backwards in flaccid penis).Ventral surface is marked by a median raphe.
Structure
The human penis is made up of three columns of tissue: two corpora cavernosa lie next to each other on the dorsal side and one corpus spongiosum lies between them on the ventral side.
The enlarged and bulbous-shaped end of the corpus spongiosum forms the glans penis, which supports the foreskin or prepuce, a loose fold of skin that in adults can retract to expose the glans. The area on the underside of the penis, where the foreskin is attached, is called the frenum (or frenulum).
The urethra, which is the last part of the urinary tract, traverses the corpus spongiosum, and its opening, known as the meatus (Template:Pron-en), lies on the tip of the glans penis. It is a passage both for urine and for the ejaculation of semen. Sperm are produced in the testes and stored in the attached epididymis. During ejaculation, sperm are propelled up the vas deferens, two ducts that pass over and behind the bladder. Fluids are added by the seminal vesicles and the vas deferens turns into the ejaculatory ducts which join the urethra inside the prostate gland. The prostate as well as the bulbourethral glands add further secretions, and the semen is expelled through the penis.
The 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 (opening of the urethra) across the scrotum to the perineum (area between scrotum and anus).
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. It cannot be withdrawn into the groin, and it is larger than average in the animal kingdom in proportion to body mass.
Penile growth and puberty
On entering puberty, the penis, scrotum and testicles will begin to develop. During the process, pubic hair grows above and around the penis. A large-scale study assessing penis size in thousands of 17-19 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.[4]
Sexual homology
In short, this is a known list of sex organs that evolve from the same tissue in a human life.
The glans of the penis is homologous to the clitoral glans; the corpora cavernosa are homologous to the body of the clitoris; the corpus spongiosum is homologous to the vestibular bulbs beneath the labia minora; the scrotum, homologous to the labia minora and labia majora; and the foreskin, homologous to the clitoral hood. The raphe does not exist in females, because there, the two halves are not connected.
Erection
An erection is the stiffening and rising (see Erection Angle) of the penis, which occurs during sexual arousal, though it can also happen in non-sexual situations. 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, causing it to lengthen and stiffen. 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.
Erection angle
Although many erect penises point upwards (see illustration), it is common and normal for the erect penis to point nearly vertically upwards or nearly vertically downwards or even horizontally straight forward, all depending on 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. 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.[5]
| Angle (degrees) | Percent |
|---|---|
| 0–30 | 5 |
| 30–60 | 30 |
| 60–85 | 31 |
| 85–95 | 10 |
| 95–120 | 20 |
| 120–180 | 5 |
Ejaculation
Ejaculation is the ejecting of semen from the penis, and is usually accompanied by orgasm. A series of muscular contractions delivers semen, containing male gametes known as sperm cells or spermatozoa, from the penis (and into the vagina, if for reproductive intention via sexual intercourse). It is usually the result of sexual stimulation, which may include prostate stimulation. Rarely, it is due to prostatic disease. Ejaculation may occur spontaneously during sleep (a nocturnal emission or wet dream). Anejaculation is the condition of being unable to ejaculate.
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.
Normal variations
- Pearly penile papules are raised bumps of somewhat paler color around the base of the glans and are normal.
- Fordyce's spots are small, raised, yellowish-white spots 1–2 mm in diameter that may appear on the penis.
- 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, is harmless in infancy and pre-pubescence, occurring in about 8% of boys at age 10. According to the British Medical Association, treatment (steroid cream, 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.
Disorders
Paraphimosis is an inability to move the foreskin forward, over the glans. It can result from fluid trapped in a foreskin which is 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 benefit from 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.
Infection with the herpes virus can occur after sexual contact with an infected carrier; this may lead to the development of herpes sores.
Pudendal nerve entrapment is a condition characterized by pain on sitting and loss of penile (or clitoral) 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. Prompt medical attention lowers 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 or impotence is the inability to have and maintain an erection sufficiently firm for satisfactory sexual performance. Diabetes is a leading cause, as is natural aging. A variety of treatments exist, including drugs, such as sildenafil citrate (marketed as Viagra) which works by vasodilation.
Priapism is a painful and potentially harmful medical condition in which the erect penis does not return to its flaccid state. 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 necessitate amputation. The condition has been associated with a variety of drugs including prostaglandin but not sildenafil (Viagra).[6]
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. Circumcision is said to protect against this disease but this notion remains controversial.[7]
Developmental disorders
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.[8] It is usually corrected by surgery. The Intersex Society of North America classifies hypospadias as an intersex condition. They believe in halting all medically unnecessary surgeries, including many of those done on people with hypospadias.
A micropenis is a very small penis caused by developmental or congenital problems. Diphallia, or penile duplication (PD), is the condition of having two penises. However, this disorder is exceedingly rare.
Alleged and observed psychological disorders
- 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, West Africa's '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.[9]
- Penis envy—the contested Freudian belief of a woman envying men for having a penis.
Altering the genitalia
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, the apadravya, the ampallang, the dydoe, and the frenum piercing. Foreskin restoration or stretching is a further form of body modification, as well as implants under the shaft of the penis. Male to female transsexuals who undergo sex reassignment surgery, have their penis surgically modified into a neovagina. Female to male transsexuals may have a phalloplasty.
Other practices which alter the penis are also performed, although they are rare in Western societies without a diagnosed medical condition. Apart from a 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.
Circumcision
The most common form of genital alteration is circumcision: removal of part or all of the foreskin for various cultural, religious, and more rarely medical reasons. For infant circumcision, modern devices such as the Gomco clamp, Plastibell, and Mogen clamp are available.[10]
With all modern devices the same basic procedure is followed. First, the amount of foreskin to be removed is estimated. The foreskin is then opened via the preputial orifice to reveal the glans underneath and ensure it is normal. The inner lining of the foreskin (preputial epithelium) is then separated from its attachment to the glans. The device is then placed (this sometimes requires a dorsal slit) and remains there until blood flow has stopped. Finally, part, or all, of the foreskin is then removed.
Adult circumcisions are often performed without clamps and require 4 to 6 weeks of abstinence from masturbation or intercourse after the operation to allow the wound to heal.[11] In some African countries, male circumcision is often performed by non-medical personnel under unsterile conditions.[12] After hospital circumcision, the foreskin may be used in biomedical research,[13] consumer skin-care products,[14] skin grafts,[15][16][17] or β-interferon-based drugs.[18] In parts of Africa, the foreskin may be dipped in brandy and eaten by the patient, eaten by the circumciser, or fed to animals.[19] According to Jewish law, after a Brit milah, the foreskin should be buried.[20]
There is controversy surrounding circumcision. Advocates of circumcision argue, for example, that it provides important health advantages which outweigh the risks, has no substantial effects on sexual function, has a low complication rate when carried out by an experienced physician, and is best performed during the neonatal period.[21] Opponents of circumcision argue, for example, that it is a practice which has historically been, and continues to be, defended through the use of various myths; that it interferes with normal sexual function; is extremely painful; and when performed on infants and children violates the individual's human rights.[22]
The American Medical Association stated in 1999: "Virtually all current policy statements from specialty societies and medical organizations do not recommend routine neonatal circumcision, and support the provision of accurate and unbiased information to parents to inform their choice."[23]
The World Health Organization (WHO; 2007), the Joint United Nations Programme on HIV/AIDS (UNAIDS; 2007), and the Centers for Disease Control and Prevention (CDC; 2008) state that evidence indicates male circumcision significantly reduces the risk of HIV acquisition by men during penile-vaginal sex, but also state that circumcision only provides partial protection and should not replace other interventions to prevent transmission of HIV.[24][25]
Surgical replacement
The first successful penis allotransplant surgery was done on September 2005 in a military hospital in Guangzhou, China.[26] 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 newly brain-dead man, age 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, the surgery was reversed because of a severe psychological problem (rejection) by the recipient and his wife.[27]
In 2009 researchers Chen, Eberli, Yoo and Atala have produced bioengineered penises and implanted them on rabbits.[28] The animals 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.
Size
While results vary across studies, the consensus is that the average erect human penis is approximately 12.9–15 cm (5.1–5.9 in) in length with 95% of adult males falling within the interval (10.7 cm, 19.1 cm) or (4.23 in, 7.53 in).[29][30][31] The typical girth or circumference is approximately 12.3 cm (4.84 in) when fully erect. The average penis size is slightly larger than the median size (i.e. most penises are below average in size).
A research project, summarizing dozens of published studies conducted by physicians of different nationalities, shows that worldwide, erect-penis size averages vary between 9.6 and 16 cm (3.8 and 6.3 in). It has been suggested that this difference is caused not only by genetics, but also by environmental factors such as culture, diet, chemical/pollution exposure,[32][33][34] etc. Endocrine disruption resulting from chemical exposure has been linked to genital deformation in both sexes (among many other problems).
The longest officially documented human penis was found by Doctor Robert Latou Dickinson. It was 34.3 cm (13.5 in) long and 15.9 cm (6.26 in) around.[35]
Species morphology
As a general rule, an animal's penis is proportional to its body size, but this varies greatly between species — even between closely related species. For example, an adult gorilla's erect penis is about 4 cm (1.5 in) in length; an adult chimpanzee, significantly smaller (in body size) than a gorilla, has a penis size about double that of the gorilla. In comparison, the human penis is larger than that of any other primate, both in proportion to body size and in absolute terms.
As with any other bodily attribute, the length and girth of the penis can be highly variable between individuals of the same species. In many animals, especially mammals, the size of a flaccid penis is much smaller than its erect size.
Most marsupials, except for the two largest species of kangaroos, have a bifurcated penis. That is, it separates into two columns, and so the penis has two ends.
In the realm of absolute size, the smallest vertebrate penis belongs to the common shrew (5 mm or 0.2 inches). Accurate measurements of the blue whale are difficult to take because the whale's erect length can only be observed during mating.
The Icelandic Phallological Museum is devoted entirely to collecting penis specimens from all sorts of land and sea mammals.
Echidnas have a four-headed penis, but only two of the heads are used during mating. The other two heads "shut down" and do not grow in size. The heads used are swapped each time the mammal has sex.[36]
Most male birds (e.g. roosters and turkeys) have a cloaca (also present on the female), but not a penis. Among bird species with a penis are paleognathes (tinamous and ratites), Anatidae (ducks, geese and swans), and a very few other species (including ostriches and flamingoes). A bird penis is different in structure from mammal penises, being an erectile expansion of the cloacal wall and being erected by lymph, not blood. It is usually partially feathered and in some species features spines and brush-like filaments, and in flaccid state curls up inside the cloaca. The Argentine Blue-bill has the largest penis in relation to body size of all vertebrates; while usually about half the body size (20 cm), a specimen with a remarkable 42.5 cm-long penis is documented.
Male specimens of the Squamata order of reptiles have two paired organs called hemipenes. In fish, the gonopodium, andropodium, and claspers are various organs developed from modified fins. In male insects, the structure analogous to a penis is known as aedeagus. The male copulatory organ of various lower invertebrate animals is often called the cirrus.
The record for the largest penis to body size ratio is held by the barnacle. The barnacle's penis can grow to up to forty times its own body length. This enables them to reach the nearest female.[37]
Cultural aspects
Uses of animal penises
- Culinary, e.g., in Chinese gastronomy
- Magical and therapeutic, in medicine and/or superstition, especially as an alleged aphrodisiac or even cure for impotence
- Punitive implements, such as the bull pizzle
- Dog chew toys, such as the bull pizzle
Uses of human penises in cultural traditions
- Aesthetic, e.g., Body modification
- For the symbolic and artistic use, see under phallus; in heraldry, the term is pizzle
- In humor, considered indecent or completely taboo in various cultures
- Religious veneration, see St. Priapus Church[dubious – discuss]
See also
- Baculum
- Erogenous zone
- Dildo
- Koteka
- Micropenis
- Penis enlargement
- Castration complex
- Penis envy
- Penis Plant
- Penis removal
- Phallophilia
- Phallus
- Preputial mucosa
- Preputioplasty
- Pseudo-penis
- Pubic Hair
- Stunt cock
- Testicles
- Vagina
References
- ^ Simpson, John; Weiner, Edmund, eds. (1989). "yard, n.2". Oxford English Dictionary (2nd ed.). Oxford University Press. Online edition, print version ISBN 978-0-19-861186-8, CD-ROM ISBN 978-0-19-861016-8.
- ^ Simpson, John, ed. (2005). "penis, n.". Oxford English Dictionary (Draft revision September 2005 ed.). Oxford University Press. Online edition. (1989 second edition: ISBN 978-0-19-861186-8, CD-ROM ISBN 978-0-19-861016-8)
- ^ Online Etymology Dictionary
- ^ Ponchietti, R.; et al. (2001). "Penile length and circumference: a study on 3,300 young Italian males". European Urology. 39 (2). Italy: 183–186.
{{cite journal}}: Explicit use of et al. in:|author=(help); Unknown parameter|month=ignored (help) - ^ Penile Erections: Shape, Angle and Length. Journal of Sex & Marital Therapy 1997 Fall;23(3):195-207
- ^ Goldenberg M,Safety and Efficacy of sildenafil citrate in the treatment of male erectile dysfunction. Clin Ther. 1998,20(6):1033–48.
- ^ Boczko S & Freed S, Penile Carcinoma in Circumcised Males. 1979, NY State Journal of Medicine, 79(12), 1903–1904.
- ^ Iatrogenic hypospadias--a preventable injury?
- ^ Reuters, Lynchings in Congo as penis theft panic hits capital
- ^ Holman, John R. (1995). "Neonatal circumcision techniques – includes patient information sheet" ([dead link] – Scholar search). American Family Physician. 52 (2): 511–520. ISSN 0002-838X PMID 7625325. Retrieved 2006-06-29.
{{cite journal}}: External link in|format=|coauthors=ignored (|author=suggested) (help); Unknown parameter|month=ignored (help) - ^ Holman, J.R. (1999). "Adult circumcision". American Family Physician. 59 (6): 1514–1518. PMID 10193593.
{{cite journal}}: Unknown parameter|coauthors=ignored (|author=suggested) (help); Unknown parameter|month=ignored (help) - ^ "In Africa, a problem with circumcision and AIDS".
- ^ Hovatta, O. (2003). "A culture system using human foreskin fibroblasts as feeder cells allows production of human embryonic stem cells". Human Reproduction. 18 (7): 1404–1409. doi:10.1093/humrep/deg290. PMID 12832363.
{{cite journal}}: Unknown parameter|coauthors=ignored (|author=suggested) (help); Unknown parameter|month=ignored (help) - ^ "The Skinny On 'Miracle' Wrinkle Cream". NBC10.com. NBC Universal, Inc. 2002. Retrieved 2008-08-20.
{{cite web}}: Unknown parameter|month=ignored (help) - ^ "High-Tech Skinny on Skin Grafts". www.wired.com:science:discoveries. CondéNet, Inc. 02.16.99. Retrieved 2008-08-20.
{{cite web}}: Check date values in:|date=(help) - ^ "Skin Grafting". www.emedicine.com. WebMD. Retrieved 2008-08-20.
- ^ Amst, Catherine (July 27, 1998). "Biotech Bodies". www.businessweek.com. The McGraw-Hill Companies Inc. Retrieved 2008-08-20.
{{cite web}}: Unknown parameter|coauthors=ignored (|author=suggested) (help) - ^ Cowan, Alison Leigh (April 19, 1992). "Wall Street; A Swiss Firm Makes Babies Its Bet". New York Times:Business. New York Times. Retrieved 2008-08-20.
- ^ Anonymous (editorial) (1949-12-24). "A ritual operation". British Medical Journal. 2: 1458–1459. PMC 2051965.
"...in parts of West Africa, where the operation is performed at about 8 years of age, the prepuce is dipped in brandy and eaten by the patient; in other districts the operator is enjoined to consume the fruits of his handiwork, and yet a further practice, in Madagascar, is to wrap the operation specifically in a banana leaf and feed it to a calf."
{{cite journal}}:|access-date=requires|url=(help) - ^ Shulchan Aruch, Yoreh Deah, 265:10
- ^ Schoen, Edgar J (December 1, 2007). "Should newborns be circumcised? Yes". Can Fam Physician. 53 (12): 2096–8, 2100–2. PMC 2231533. PMID 18077736. Retrieved 2008-05-02.
- ^ Milos, Marilyn Fayre (1992). "Circumcision: A medical or a human rights issue?". Journal of Nurse-Midwifery. 37 (2 S1): S87–S96. doi:10.1016/0091-2182(92)90012-R. PMID 1573462. Retrieved 2007-04-06.
{{cite journal}}: Unknown parameter|coauthors=ignored (|author=suggested) (help); Unknown parameter|month=ignored (help) - ^ "Report 10 of the Council on Scientific Affairs (I-99):Neonatal Circumcision". 1999 AMA Interim Meeting: Summaries and Recommendations of Council on Scientific Affairs Reports. American Medical Association. 1999. p. 17. Retrieved 2006-06-13.
{{cite web}}: Unknown parameter|month=ignored (help) - ^ "New Data on Male Circumcision and HIV Prevention: Policy and Programme Implications" (PDF). World Health Organization. March 28, 2007. Retrieved 2007-08-13.
{{cite journal}}: Cite journal requires|journal=(help) - ^ "Male Circumcision and Risk for HIV Transmission and Other Health Conditions: Implications for the United States". Centers for Disease Control and Prevention. 2008.
- ^ Guangzhou Daily
- ^ Man rejects first penis transplant | Science | The Guardian
- ^ Chen, K.-L., Eberli, D., Yoo, J.J, & Atala, A. (2009). "Bioengineered corporal tissue for structural and functional restoration of the penis". PNAS. doi:10.1073/pnas.0909367106.
{{cite journal}}: CS1 maint: multiple names: authors list (link) - ^ Wessels, H (1996-09-01). "Penile Length in the Flaccid and Erect States: Guidelines for Penile Augmentation". Retrieved 2007-06-05.
- ^ Chen, J (2000-12-01). "Predicting penile size during erection". Retrieved 2006-09-23.
- ^ "ANSELL RESEARCH - The Penis Size Survey". 2001. Retrieved 2006-07-13.
{{cite web}}: Unknown parameter|month=ignored (help) - ^ "Size decrease in Male infants with prenatal phthalate exposure". ehp. Retrieved 2006-11-08.
- ^ "PCBs DIMINISH PENIS SIZE". Retrieved 2007-04-09.
- ^ "Hormone Hell". DISCOVER. Retrieved 2008-04-05.
- ^ Dickinson, R.L., 1940. The Sex Life of the Unmarried Adult. New York: Vanguard Press
- ^ Shultz, N. (2007-10-26). "Exhibitionist spiny anteater reveals bizarre penis". New Scientist website. Retrieved 2006-10-27.
{{cite web}}: External link in|work= - ^ The Largest Penis in the World - Both for humans and animals, size does matter! - Softpedia
External links
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