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Undid revision 513351199 by Dr. Blofeld (talk) revert, it's not reasonable to convert a human organ into a prose. If you insist, pls discuss on talk first
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===Size===
===Size===
{{Main|Human penis size}}
{{Main|Human penis size}}
[[File:Penis percentile.svg|thumb|right|320px|Results from LifeStyles condom manufacturer's study of penis size, displayed in inches. The data is listed by [[percentile]] (i.e. a male with a {{convert|6|in|cm|2|abbr=on}} penis is greater in length than 70 percent of those measured.)]]
While results vary across studies, the consensus is that the average [[erection|erect]] human penis is approximately {{convert|12.9|-|15|cm|in|1|abbr=on}} in length with 95% of adult males falling within the interval (10.7&nbsp;cm, 19.1&nbsp;cm) or (4.23 in, 7.53 in). Neither patient age nor size of the flaccid penis accurately predicted erectile length. Stretched length most closely correlated with erect length.<ref name="Wessells">{{Cite journal|author=Wessells H, Lue TF, McAninch JW |title=Penile length in the flaccid and erect states: guidelines for penile augmentation |journal=The Journal of Urology |volume=156 |issue=3 |pages=995–7 |year=1996 |month=September |pmid=8709382 |doi=10.1016/S0022-5347(01)65682-9}}</ref><ref name="Chen">{{Cite journal|author=Chen J, Gefen A, Greenstein A, Matzkin H, Elad D |title=Predicting penile size during erection |journal=International Journal of Impotence Research |volume=12 |issue=6 |pages=328–33 |year=2000 |month=December |pmid=11416836 |doi=10.1038/sj.ijir.3900627}}</ref><ref name="lifestyles_condoms">{{cite web
While results vary across studies, the consensus is that the average [[erection|erect]] human penis is approximately {{convert|12.9|-|15|cm|in|1|abbr=on}} in length with 95% of adult males falling within the interval (10.7&nbsp;cm, 19.1&nbsp;cm) or (4.23 in, 7.53 in). Neither patient age nor size of the flaccid penis accurately predicted erectile length. Stretched length most closely correlated with erect length.<ref name="Wessells">{{Cite journal|author=Wessells H, Lue TF, McAninch JW |title=Penile length in the flaccid and erect states: guidelines for penile augmentation |journal=The Journal of Urology |volume=156 |issue=3 |pages=995–7 |year=1996 |month=September |pmid=8709382 |doi=10.1016/S0022-5347(01)65682-9}}</ref><ref name="Chen">{{Cite journal|author=Chen J, Gefen A, Greenstein A, Matzkin H, Elad D |title=Predicting penile size during erection |journal=International Journal of Impotence Research |volume=12 |issue=6 |pages=328–33 |year=2000 |month=December |pmid=11416836 |doi=10.1038/sj.ijir.3900627}}</ref><ref name="lifestyles_condoms">{{cite web
| url = http://www.free-condom-stuff.com/education/research.htm
| url = http://www.free-condom-stuff.com/education/research.htm

Revision as of 07:46, 21 September 2012

Human penis
A flaccid penis with labels showing the locations of the shaft, foreskin, glans and meatus. The model has removed body hair.
Details
PrecursorGenital tubercle, Urogenital folds
ArteryDorsal artery of the penis, deep artery of the penis, artery of the urethral bulb
VeinDorsal veins of the penis
NerveDorsal nerve of the penis
LymphSuperficial inguinal lymph nodes
Identifiers
Latin'penis, penes'
MeSHD010413
TA98A09.4.01.001
TA23662
FMA9707
Anatomical terminology

The human penis is an external sexual organ of male humans. It is a reproductive, intromittent organ that additionally serves as the urinal duct.

Human anatomy

Parts

  • Root of the penis (radix): It is the attached part, consisting of the bulb of penis in the middle and the 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 the erect penis), and ventral or urethral (facing downwards and backwards in the flaccid penis). The ventral surface is marked by a groove in a lateral direction.
  • Epithelium of the penis consists of the shaft skin, the foreskin, the and the preputial mucosa on the inside of the foreskin and covering the glans penis.

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 rounded base of the glans is called the corona. The perineal raphe is the noticeable line along the underside of the penis.

Anatomical diagram of a human penis

The urethra, which is the last part of the urinary tract, traverses the corpus spongiosum, and its opening, known as the meatus (/[invalid input: 'icon']miːˈeɪtəs/), 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.

Physiological functions of the penis

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.[1]

Sexual homology

Stages of the development
Main article: Sexual homology

In short, this is a known list of sex organs that evolve from the same tissue in females and males.

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

Main article: Erection
The development of a penile erection, also showing the foreskin gradually retracting over the glans.
See also: Commons image gallery
A ventral view of a penis flaccid (left) and erect (middle); a dorsal view of a penis erect (right).

An erection is the stiffening and rising 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, out of a sample of 1,564 males aged 20 through 69. 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.[2]

Occurrence of erection angles
angle (º)
from vertically upwards 		Percent
of males
0–30 5
30–60 30
60–85 31
85–95 10
95–120 20
120–180 5

Ejaculation

Main article: 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. 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 (known as 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 (sulcus) of the glans which typically develop in men aged 20 to 40, and around 10% of all men are affected. They may be mistaken for warts, but are not harmful or infectious and require no treatment.[3]
  • Fordyce's spots are small, raised, yellowish-white spots 1–2 mm 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, is 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.

Disorders

  • 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 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 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, 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).[4]
  • 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.[5]

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.[6] 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 extremely 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.[7]
  • Penis envy – the contested Freudian belief of all women inherently envying men for having penises.

Altering the genitalia

Main article: 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, 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 that 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.

Penis removal is another form of alteration done to the penis.

Circumcision

Main article: Circumcision
A labelled dorsal view of a circumcised penis: (1)Shaft, (2)Circumcision scar, (3)Corona, (4)Glans, (5)Meatus.

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.[8]

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 ensured that 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.[9] In some African countries, male circumcision is often performed by non-medical personnel under unsterile conditions.[10] After hospital circumcision, the foreskin may be used in biomedical research,[11] consumer skin-care products,[12] skin grafts,[13][14][15] or β-interferon-based drugs.[16] In parts of Africa, the foreskin may be dipped in brandy and eaten by the patient, eaten by the circumciser, or fed to animals.[17] According to Jewish law, after a Brit milah, the foreskin should be buried.[18]

There is controversy surrounding circumcision. Advocates of circumcision argue, for example, that it provides important health advantages that 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.[19] Opponents of circumcision argue, for example, that the practice has been and is still defended through the use of various myths; that it interferes with normal sexual function; that it is extremely painful; and that when performed on infants and children, it violates the individual's human rights.[20]

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."[21]

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.[22][23] In addition, some doctors have expressed concern over the policy and the data that supports it.[24][25]

Surgical replacement

The first successful penis allotransplant surgery was done in 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 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.[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 or phalloplasties.

Size

Main article: Human penis 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). Neither patient age nor size of the flaccid penis accurately predicted erectile length. Stretched length most closely correlated with erect length.[29][30][31] The average penis size is slightly larger than the median size (i.e., most penises are below average in size).

Length of the flaccid penis does not necessarily correspond to length of the erect penis; some smaller flaccid penises grow much longer, while some larger flaccid penises grow comparatively less.[32] Among all apes, the human penis is the largest, both in length and girth.[33]

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 fertility medications,[34] culture, diet, and chemical/pollution exposure.[35][36][37] 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.[38]

Cultural aspects

References

  1. ^ Ponchietti R, Mondaini N, Bonafè M, Di Loro F, Biscioni S, Masieri L (2001). "Penile length and circumference: a study on 3,300 young Italian males". European Urology. 39 (2): 183–6. doi:10.1159/000052434. PMID 11223678. {{cite journal}}: Unknown parameter |month= ignored (help)CS1 maint: multiple names: authors list (link)
  2. ^ Sparling J (1997). "Penile erections: shape, angle, and length". Journal of Sex & Marital Therapy. 23 (3): 195–207. doi:10.1080/00926239708403924. PMID 9292834.
  3. ^ Spots on the penis
  4. ^ Goldenberg MM (1998). "Safety and efficacy of sildenafil citrate in the treatment of male erectile dysfunction". Clinical Therapeutics. 20 (6): 1033–48. doi:10.1016/S0149-2918(98)80103-3. PMID 9916601.
  5. ^ Boczko S, Freed S (1979). "Penile carcinoma in circumcised males". New York State Journal of Medicine. 79 (12): 1903–4. PMID 292845. {{cite journal}}: Unknown parameter |month= ignored (help)
  6. ^ Andrews HO, Nauth-Misir R, Shah PJ (1998). "Iatrogenic hypospadias—a preventable injury?". Spinal Cord. 36 (3): 177–80. doi:10.1038/sj.sc.3100508. PMID 9554017. {{cite journal}}: Unknown parameter |month= ignored (help)CS1 maint: multiple names: authors list (link)
  7. ^ Reuters, Lynchings in Congo as penis theft panic hits capital
  8. ^ Holman JR, Lewis EL, Ringler RL (1995). "Neonatal circumcision techniques". American Family Physician. 52 (2): 511–8, 519–20. PMID 7625325. {{cite journal}}: Unknown parameter |month= ignored (help)CS1 maint: multiple names: authors list (link)
  9. ^ Holman JR, Stuessi KA (1999). "Adult circumcision". American Family Physician. 59 (6): 1514–8. PMID 10193593. {{cite journal}}: Unknown parameter |month= ignored (help)
  10. ^ "In Africa, a problem with circumcision and AIDS".
  11. ^ Hovatta O, Mikkola M, Gertow K; et al. (2003). "A culture system using human foreskin fibroblasts as feeder cells allows production of human embryonic stem cells". Human Reproduction. 18 (7): 1404–9. doi:10.1093/humrep/deg290. PMID 12832363. {{cite journal}}: Explicit use of et al. in: |author= (help); Unknown parameter |month= ignored (help)CS1 maint: multiple names: authors list (link)
  12. ^ "'Miracle' Wrinkle Cream's Key Ingredient". Banderasnews.com. Banderas News, Inc. 2008. Retrieved 2010-10-22. {{cite web}}: Unknown parameter |month= ignored (help)
  13. ^ "High-Tech Skinny on Skin Grafts". www.wired.com:science:discoveries. CondéNet, Inc. 1999-02-16. Retrieved 2008-08-20.
  14. ^ "Skin Grafting". www.emedicine.com. WebMD. Retrieved 2008-08-20.
  15. ^ 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)
  16. ^ 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.
  17. ^ Anonymous (editorial) (1949-12-24). "A ritual operation". British Medical Journal. 2: 1458–1459. doi:10.1136/bmj.2.4642.1458. PMC 2051965. PMID 20787713. ...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)
  18. ^ Shulchan Aruch, Yoreh Deah, 265:10
  19. ^ Schoen EJ (2007). "Should newborns be circumcised? Yes". Canadian Family Physician. 53 (12): 2096–8, 2100–2. PMC 2231533. PMID 18077736. {{cite journal}}: Unknown parameter |month= ignored (help)
  20. ^ Milos MF, Macris D (1992). "Circumcision. A medical or a human rights issue?". Journal of Nurse-midwifery. 37 (2 Suppl): 87S–96S. doi:10.1016/0091-2182(92)90012-R. PMID 1573462.
  21. ^ "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)
  22. ^ "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)
  23. ^ "Male Circumcision and Risk for HIV Transmission and Other Health Conditions: Implications for the United States". Centers for Disease Control and Prevention. 2008.
  24. ^ G. Dowsett, M. Couch. "Male Circumcision and HIV Prevention: Is There Really Enough of the Right Kind of Evidence?". Reproductive Health Matters.
  25. ^ Vardi Y, Sadeghi-Nejad H, Pollack S, Aisuodionoe-Shadrach OI, Sharlip ID (2007). "Male circumcision and HIV prevention". J Sex Med. 4 (4 Pt 1): 838–43. doi:10.1111/j.1743-6109.2007.00511.x. PMID 17627731. {{cite journal}}: Unknown parameter |month= ignored (help)CS1 maint: multiple names: authors list (link)
  26. ^ Guangzhou Daily
  27. ^ Sample, Ian (2006-09-18). "Man rejects first penis transplant". The Guardian. London. Retrieved 2010-05-22.
  28. ^ Chen KL, Eberli D, Yoo JJ, Atala A (2009). "Regenerative Medicine Special Feature: Bioengineered corporal tissue for structural and functional restoration of the penis". Proceedings of the National Academy of Sciences of the United States of America. 107 (8): 3346–50. doi:10.1073/pnas.0909367106. PMC 2840474. PMID 19915140. {{cite journal}}: Unknown parameter |month= ignored (help)CS1 maint: multiple names: authors list (link)
  29. ^ Wessells H, Lue TF, McAninch JW (1996). "Penile length in the flaccid and erect states: guidelines for penile augmentation". The Journal of Urology. 156 (3): 995–7. doi:10.1016/S0022-5347(01)65682-9. PMID 8709382. {{cite journal}}: Unknown parameter |month= ignored (help)CS1 maint: multiple names: authors list (link)
  30. ^ Chen J, Gefen A, Greenstein A, Matzkin H, Elad D (2000). "Predicting penile size during erection". International Journal of Impotence Research. 12 (6): 328–33. doi:10.1038/sj.ijir.3900627. PMID 11416836. {{cite journal}}: Unknown parameter |month= ignored (help)CS1 maint: multiple names: authors list (link)
  31. ^ "ANSELL RESEARCH – The Penis Size Survey". 2001. Retrieved 2006-07-13. {{cite web}}: Unknown parameter |month= ignored (help)
  32. ^ "Penis Size FAQ & Bibliography". Kinsey Institute. 2009.
  33. ^ Penis size: An evolutionary perspective retrieved 10 February 2012
  34. ^ Center of Disease Control. "DES Update: Consumers".
  35. ^ Swan SH, Main KM, Liu F; et al. (2005). "Decrease in anogenital distance among male infants with prenatal phthalate exposure". Environmental Health Perspectives. 113 (8): 1056–61. doi:10.1289/ehp.8100. PMC 1280349. PMID 16079079. {{cite journal}}: Explicit use of et al. in: |author= (help); Unknown parameter |month= ignored (help)CS1 maint: multiple names: authors list (link)
  36. ^ Montague, Peter. "PCBs Diminish Penis Size". Rachel's Hazardous Waste News. 372.
  37. ^ "Hormone Hell". DISCOVER. Retrieved 2008-04-05.
  38. ^ Dickinson, R.L. (1940). The Sex Life of the Unmarried Adult. New York: Vanguard Press.[page needed]
  39. ^ Fritscher, Jack (2004). Popular witchcraft: straight from the witch's mouth. Popular Press. p. 161. ISBN 978-0-299-20304-7. {{cite book}}: Unknown parameter |coauthors= ignored (|author= suggested) (help)
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