foreskin

Foreskin
Latinprepucium, præputium
subject #262 1250
ArteryDorsal artery of the penis
VeinSuperficial dorsal vein of the penis
NerveDorsal nerve of the penis
PrecursorGenital tubercle, Urogenital folds
MeSH Foreskin
The foreskin or prepuce (a technically broader term that also includes the clitoral hood, the homologous structure in women) is a retractable double-layered fold of skin and mucous membrane that covers the glans penis and protects the urinary meatus when the penis is not erect. Almost all mammals have foreskins, although in these non-human cases the foreskin is usually a sheath into which the whole penis is retracted. Only monotremes (the platypus and the echidna) lack foreskins.[1]

The human foreskin

Description

Enlarge picture
The Male Anatomy


In humans, the outside of the foreskin is like the skin on the shaft of the penis but the inner foreskin is a mucous membrane like the inside of the eyelid or the mouth. Like the eyelid, the foreskin is free to move. Smooth muscle fibres keep it close to the glans but make it highly elastic.[2] The foreskin is attached to the glans with a frenulum which helps retract the foreskin over the glans. At the end of foreskin there is a band of tissue called the ridged band which, according to one study, is rich in nerve endings called Meissner's corpuscles.[3] According to a NOCIRC-funded study by Sorrells et al., the five most sensitive areas of the penis are on the foreskin.[4]

In children, the foreskin covers the glans completely but in adults this need not be so. Schöberlein [5] found that about 50% of young men had full coverage of the glans, 42% had partial coverage, and in the remaining 8%, the glans was uncovered. After adjusting for circumcision, he stated that in 4% of the young men the foreskin had spontaneously atrophied (shrunk).

Development

Eight weeks after fertilization, the foreskin begins to grow over the head of the penis, covering it completely by 16 weeks. At this stage the foreskin and glans share an epithilium (mucous layer) that fuses the two together. It remains this way until the foreskin separates from the glans.[6]

At birth, the foreskin is usually still fused with the glans.[6] As childhood progresses the foreskin and the glans gradually separate, a process that may not be complete until the age of 17.[7] Thorvaldsen and Meyhoff reported that average age of first foreskin retraction in Denmark is 10.4 years.[8] Wright argues that forcible retraction of the foreskin should be avoided and that the child himself should be the first one to retract his own foreskin.[9] Premature retraction may be painful, and may result in infection.

Functions

Some researchers believe that the foreskin facilitates intercourse. In her book Sex as Nature Intended It, Kristen O'Hara argues that foreskin is a natural gliding stimulator of the vaginal walls during intercourse, increasing a woman's overall clitoral stimulation and helping a woman achieve orgasm more often and more quickly. [1] She therefore believes that the absence of the foreskin and gliding action makes it more difficult for a woman to achieve orgasm during intercourse.

Taylor et al described the foreskin in detail, documenting a ridged band of mucosal tissue. They stated "This ridged band contains more Meissner's corpuscles than does the smooth mucosa and exhibits features of specialized sensory mucosa."[10] The AAP noted that the work of Taylor et al "suggests that there may be a concentration of specialized sensory cells in specific ridged areas of the foreskin."[11] In 1999, Cold and Taylor stated "The prepuce is primary, erogenous tissue necessary for normal sexual function."<ref name="cold-taylor" /> Moses and Bailey (1998}, however, describe the evidence as "indirect," and state that "aside from anecdotal reports, it has not been demonstrated that this is associated with increased male sexual pleasure."[12]

Gairdner (1949) states that the foreskin protects the glans<ref name="gairdner" /> but some studies show that inflammation of the glans is more common when the foreskin is present.[13]

Shen (China) found a statistically significant *(p = 0.001) increase in erectile dysfunction following circumcision.[14] Pang and Kim (South Korea) reported "Of those who were circumcised long after they had been sexually active, > 80% reported no noticeable difference in sexuality, but a man was twice as likely to have experienced diminished sexuality than improved sexuality."[15] In another study by Kim and Pang (2006) of 255 men circumcised after the age of 20 and 118 who were not circumcised, they reported that masturbatory pleasure decreased in 48% of the respondents and increased in 8%. Masturbatory difficulty increased in 63% but was easier in 37%. 20% reported that their sex life was worse after circumcision and 6% reported that it had improved (the abstract is silent about the other 74%). "There were no significant differences in sexual drive, erection, ejaculation, and ejaculation latency time between circumcised and uncircumcised men." They concluded, "There was a decrease in masturbatory pleasure and sexual enjoyment after circumcision, indicating that adult circumcision adversely affects sexual function in many men, possibly because of complications of the surgery and a loss of nerve endings." [2] [3] Sorrells et al. (2007), in a study funded by NOCIRC, compared penile sensitivity in 91 circumcised and 68 uncircumcised men and concluded, "The transitional region from the external to the internal prepuce is the most sensitive region of the uncircumcised penis and more sensitive than the most sensitive region of the circumcised penis."[4]

Fink's study of American men also found significantly worsened erectile function *(p = 0.01)[16] Other studies came to different conclusions. Collins (USA), Senkul (Turkey), and Masood (Britain) found no significant difference in erectile function.[17][18][19] Senkul found that the circumcised men took significantly longer to ejaculate after circumcision *(P = 0.02).<ref name="senkul" /> Laumann's study of American-born men found "little difference between circumcision status and sexual dysfunction for the two younger cohorts" (18-29 and 30-44). However, older men (45-59) with foreskins in his sample were significantly more likely to suffer from erectile dysfunction overall *(p < 0.05) and trouble achieving and maintaining an erection *(p. < 0.05). Premature ejaculation and performance anxiety were also noted *(both p. < 0.10). Circumcision rates were also significantly different in different ethnic groups (less common in Blacks and Hispanics) and they varied with the education level of the mother (less common in those with less education).[20][21]

Fink's study reported less sensitivity after circumcision, though this only bordered on statistical significance *(p = 0.08).<ref name="fink" /> In contrast, Masood et al. reported improved sensation in 38% of men following circumcision and less sensation in 18%. 61% expressed greater satisfaction following removal of the foreskin, less satisfaction in 17%, and no change in 22%.[22]

Interpretation of these findings vary. For example, Masood said, "Penile sensitivity had variable outcomes after circumcision. The poor outcome of circumcision considered by overall satisfaction rates suggests that when we circumcise men, these outcome data should be discussed during the informed consent process."<ref name="masood" /> Hill and Denniston listed Senkul's finding of an increased ejaculatory time as a "demonstrated adverse effect" of circumcision[23] However, Senkul stated: "Adult circumcision does not adversely affect sexual function. The increase in the ejaculatory latency time can be considered an advantage rather than a complication. However, concerning the cause of that increase, in a Muslim community, the psychological influence of circumcision may be more pronounced than the organic effect."

Some do not accept that the presence or absence of the foreskin makes any difference and as such has no sexual effect.

The fold of the prepuce maintains sub-preputial wetness, which mixes with exfoliated skin to form smegma. Some authors believe that smegma contains antibacterial enzymes,[24] though their theory has been challenged.[25] Inferior hygiene has been associated with balanitis,[26] though excessive washing can cause non-specific dermatatis.[27]

The term 'gliding action' is used in some papers to describe the way the foreskin moves during sexual intercourse. A foreskin that covers the glans penis may move back and forth over the glans. This gliding movement may reduce friction during sexual intercourse. The gliding action was described by Lakshamanan & Prakash in 1980 [5]The outer layer of the prepuce in common with the skin of the shaft of the penis glides freely in a to and fro fashion... Several genital integrity activists have argued that the gliding movement of the foreskin is important during sexual intercourse:

*Warren & Bigelow claim that gliding action would help to reduce vaginal dryness and that restoration of the gliding action is an important advantage of foreskin restoration. [6]


*A survey by Bensley & Boyle provides some confirmation that gliding action provides protection of vaginal lubrication.[7] The authors explain, however, that their subjects were self-selected and a larger sample size is needed.


*O'Hara describes the gliding action:


:During intercourse, the natural penis shaft actually glides within its own shaft skin covering. This minimizes friction to the vaginal walls and opening, and to the shaft skin itself, adding immeasurably to the comfort and pleasure of both parties.''


:Friction is not entirely eliminated during natural intercourse but it is largely eliminated. Friction can take place in the lower vagina, but only if the man uses a stroke that exceeds the (forward and backward) gliding range of the shaft's extra skin. And in such a case, there will be friction only to the extent that the shaft exceeded its extra skin, which is uncommon since the natural penis has a propensity for short strokes. Primarily, it is the penis head that makes frictional contact with the vaginal walls, usually in the upper vagina where there is ample lubrication....The gliding principle of natural intercourse is a two-way street—the vagina glides on the shaft skin while the shaft skin massages the penis shaft as it glides over it. (O'Hara, p.72)


*Fleiss and Hodges claim: The foreskin's double-layered sheath enables the penile shaft skin to glide back and forth over the penile shaft. (p.24) and The foreskin enables the penis to slip in and out of the vagina nonabrasively inside its own slick sheath of self-lubricating movable skin. (p.26)


*Taylor suggests that the gliding action, where it occurs, may stimulate the nerves of the ridged band [8], and speculates that the stretching of the frenulum by the rearward gliding action during penetration triggers ejaculation. [9]


Taves used a single subject to test the actual force required to penetrate a measuring apparatus. When the foreskin was retracted a more than tenfold increase in force was needed. [10] He argued that this confirms the belief of Morgan (1967) that the foreskin makes sexual penetration easier during sexual intercourse.[11] Whiddon (1953) and Foley (1966) also believed that the presence of the foreskin made sexual penetration easier [12] [13]

A 2002 study into changing circumcision practices in Tanzania Africa, found that there was a significant move towards popularizing circumcision, mostly for perceived health reasons, but that participants (unclear whether male focus groups or female as well) reported it also led to improved sexual pleasure for men and women alike. Some participants in this context, compared the presence of a foreskin to a condom.[28]

Conditions

Frenulum breve is where the frenulum is insufficiently long to allow the foreskin to fully retract, which may lead to discomfort during intercourse. The frenulum may also tear during intercourse. Phimosis is a condition when the foreskin of an adult cannot be retracted properly. (Before adulthood, the foreskin may still be separating from the glans.[29]) Phimosis can be treated by gently stretching the foreskin, by changing masturbation habits,[30] using topical steroid ointments, preputioplasty, or by circumcision. See phimosis for more information.

A condition called paraphimosis may occur if a tight foreskin becomes trapped behind the glans and swells as a restrictive ring. This can cut off the blood supply, resulting in ischaemia of the glans penis.

Aposthia is a rare condition in which the foreskin is not present at birth.

Surgical and other modifications of the foreskin

Circumcision is the removal of the foreskin, either partially or completely. It may be done for religious, aesthetic, health, or hygiene reasons, or to treat disease.

Preputioplasty is a procedure to relieve a tight foreskin without resorting to circumcision.

Other practices include genital piercings involving the foreskin and slitting the foreskin.[31]

Research use

Foreskins obtained from circumcision procedures are frequently used by biochemical and micro-anatomical researchers to study the structure and proteins of human skin. In particular, foreskins obtained from newborns have been found to be useful in the manufacturing of more human skin.[14]

Langerhans cells

Langerhans cells are immature dendritic cells that are found in all areas of the penile epitelium,[15] but are most superficial in the inner surface of the foreskin.[16] The recent Szabo and Short (2000) study targets Langerhans cells as receptors of HIV, and states that these cells "must be regarded as the most probable sites for viral entry in primary HIV infection in men."[17] Langerhans cells are also known to express the c-type lectin langerin, which may play a role in transmission of HIV to nearby lymph nodes.[18] However, de Witte et al. (2007) reported that langerin, produced by Langerhans cells, blocks the transmission of HIV.[19]

Foreskin in non-human species

In koalas the foreskin contains naturally occurring bacteria that play an important role in fertilization.[32]

See also

References

1. ^ "Reproductive System". MSN Encarta. (2006). Seattle, WA, USA: Microsoft Corporation. 
2. ^ Lakshmanan, S; Prakash, S (1980). "Human prepuce - structure & function". Indian J Surg 44: 134-7. 
3. ^ Cold, CJ; Taylor, JR. "The prepuce". BJU Int 83 Supp 1: 34-44. 
4. ^ Sorrels, Morris; James L. Snyder, Mark D. Reiss, Christopher Eden, Marilyn F. Milos, Norma Wilcox and Robert S. Van Howe. (2007). "Fine-touch pressure thresholds in the adult penis". BJUINTERNATIONAL 99: 864–869. 
5. ^ Schöberlein circumcision taboos. Phimosis frenulum and foreskin conditions, phimosis and male initiation
6. ^ Gairdner, D (1949). "The Fate of The Foreskin: a study of circumcision". BMJ 2: 1433-7. 
7. ^ Øster, J (1968). "Further fate of the foreskin: incidence of preputial adhesions, phimosis, and smegma among Danish schoolboys". Arch Dis Child 43: 200-3. 
8. ^ Phimosis: Pathological or Physiological?
9. ^ Further to "The Further Fate of the Foreskin"
10. ^ Taylor, JR; Lockwood, AP; Taylor, AJ (1996). "The prepuce: specialized mucosa of the penis and its loss to circumcision". Br J Urol 77: 291-5. 
11. ^ (March 1999) "American Academy of Pediatrics: Circumcision Policy Statement". Pediatrics 103: 686-693. 
12. ^ Moses S; Bailey RC, Ronald AR (1998). "Male circumcision: assessment of health benefits and risks". Sexually Transmitted Infections Vol 74 (Issue 5): 368-373. Retrieved on 2007-04-28. 
13. ^ Balanitis and the uncircumcised male
14. ^ [20]
15. ^ [21]
16. ^ Adult Circumcision Outcomes Study: Effect on Erectile Function, Penile Sensitivity, Sexual Activity and Satisfaction
17. ^ Effects of Circumcision on Male Sexual Function: Debunking a Myth?
18. ^ [22]
19. ^ Circumcision in Adults: Effect on Sexual Function
20. ^ Circumcision in the United States
21. ^ Circumcision in the United States: Prevalence, Prophylactic Effects, and Sexual Practice
22. ^ Penile Sensitivity and Sexual Satisfaction after Circumcision: Are We Informing Men Correctly?
23. ^ JME -- eLetters for Holm, 30 (3) 237
24. ^ Immunological Functions of the Human Prepuce
25. ^ STI -- eLetters for Fleiss et al., 74 (5) 364-367
26. ^ [23]
27. ^ Birley: Management of Recurrent Balanitis
28. ^ Nnko et al, Dynamics of Male Circumcision Practices in Northwest Tanzania, carried out in the context of the Tanzania-Netherlands project to support AIDS control in Mwanza Region (TANESA) [24]
29. ^ Kayaba: Normal Development of the Prepuce
30. ^ The causes of adolescent phimosis
31. ^ eMedicine - Paraphimosis : Article by Jong M Choe, MD, FACS
32. ^ UQ researchers unlock another koala secret

External links

:(WMP, streaming) [25]
:(WMP, download) [26]
Latin}}} 
Official status
Official language of: Vatican City
Used for official purposes, but not spoken in everyday speech
Regulated by: Opus Fundatum Latinitas
Roman Catholic Church
Language codes
ISO 639-1: la
ISO 639-2: lat
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Arteries are muscular blood vessels that carry blood away from the heart.[1] All arteries, with the exception of the pulmonary and umbilical arteries, carry oxygenated blood.

The circulatory system is extremely important for sustaining life.
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The Dorsal Artery of the Penis ascends between the crus penis and the pubic symphysis, and, piercing the inferior fascia of the urogenital diaphragm, passes between the two layers of the suspensory ligament of the penis, and runs forward on the dorsum of the penis to the glans,
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vein is a blood vessel that carries blood toward the heart. The majority of veins in the body carry low-oxygen blood from the tissues back to the heart; the exceptions being the pulmonary and umbilical veins which both carry oxygenated blood.
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The superficial dorsal vein of the penis drains the prepuce and skin of the penis, and, running backward in the subcutaneous tissue, inclines to the right or left, and opens into the corresponding superficial external pudendal vein, a tributary of the great saphenous vein.
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A nerve is an enclosed, cable-like bundle of axons (the long, slender projection of a neuron). Neurons are sometimes called nerve cells, though this term is technically imprecise since many neurons do not form nerves, and nerves also include the glial cells that
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The dorsal nerve of the penis is the deepest division of the pudendal nerve; it accompanies the internal pudendal artery along the ramus of the ischium; it then runs forward along the margin of the inferior ramus of the pubis, between the superior and inferior layers of the fascia
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Embryology is the study of the development of an embryo. An embryo is defined as any vertebrate in a stage before birth or hatching. Embryology refers to the development of the egg cell (zygote) after fertilization and the differentiation of cells into tissues and organs.
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A genital tubercle is a body of tissue present in the development of the urinary and reproductive organs. It forms in the ventral, caudal region of mammalian embryos of both sexes, and eventually develops into a phallus.
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The urogenital folds (or urogenital ridges, or urethral folds) are an embryological structure which give rise to a portion of the external genitalia.
  • In the female, the urogenital folds become the labia minora.

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Medical Subject Headings (MeSH) is a huge controlled vocabulary (or metadata system) for the purpose of indexing journal articles and books in the life sciences. Created and updated by the United States National Library of Medicine (NLM), it is used by the MEDLINE/PubMed
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In a female human anatomy, the clitoral hood, (also called preputium clitoridis and clitoral prepuce), is a fold of skin that surrounds and protects the clitoral glans.
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In evolutionary biology, homology is any similarity between characters that is due to their shared ancestry. There are examples in different branches of biology. Anatomical structures that perform the same function in different biological species and evolved from the same structure
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The glans penis (or simply glans) is the sensitive tip of the penis. It is also commonly referred to as the "head" of the penis. Slang terms include "helmet" and "bell end".
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The urinary meatus is the external orifice of the urethra, from which urine is ejected during urination.
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Mammalia
Linnaeus, 1758

Subclasses & Infraclasses
  • Subclass †Allotheria*
  • Subclass Prototheria
  • Subclass Theria

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Monotremata
C.L. Bonaparte, 1837

Families

†Kollikodontidae
Ornithorhynchidae
Tachyglossidae
†Steropodontidae
Monotremes (from the Greek monos 'single' + trema
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The mucous membranes (or mucosae; singular: mucosa) are linings of mostly endodermal origin, covered in epithelium, and are involved in absorption and secretion. They line various body cavities that are exposed to the external environment and internal organs.
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The word frenulum on its own is often used for the frenulum of prepuce of penis, which is an elastic band of tissue under the glans penis that connects to the prepuce, or foreskin to the vernal mucosa, and helps contract the prepuce over the glans.
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The ridged band is part of the foreskin. John R. Taylor, a Canadian pathologist, medical researcher and opponent of circumcision, first described the ridged band at the Second International Symposium on Circumcision, organised by NOCIRC in San Francisco, 1991.
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Circumcision is the surgical or other cutting of some or all of the foreskin (prepuce) from the penis.[1] The word "circumcision" comes from Latin circum (meaning "around") and caedere (meaning "to cut").
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Sexual intercourse or copulation is the union of the sex organs of two sexually reproducing animals.[1] The two entities may be of opposite sexes, or they may be hermaphroditic, as is the case with snails.
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Kristen O'Hara, author and proponent of genital integrity, has researched the effects of male circumcision on sexual intercourse. Published in the British Journal of Urology, her research was described in the article The effect of male circumcision on the sexual enjoyment of the
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The sexual effects of circumcision are not well understood and researchers' findings are often contested.

Glans sensitivity

There are anecdotal reports that penile sensation and sexual satisfaction are decreased for circumcised males.
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Smegma, a transliteration of the Greek word σμήγμα for sebum, is a combination of exfoliated (shed) epithelial cells, transudated skin oils, and moisture, and can accumulate under the foreskin of males and within the vulva of females.
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The glans penis (or simply glans) is the sensitive tip of the penis. It is also commonly referred to as the "head" of the penis. Slang terms include "helmet" and "bell end".
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Sexual intercourse or copulation is the union of the sex organs of two sexually reproducing animals.[1] The two entities may be of opposite sexes, or they may be hermaphroditic, as is the case with snails.
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Foreskin restoration is the process of expanding the residual skin on the penis, via surgical or non-surgical methods, to create the appearance of a natural foreskin (prepuce) covering the glans penis.
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Kristen O'Hara, author and proponent of genital integrity, has researched the effects of male circumcision on sexual intercourse. Published in the British Journal of Urology, her research was described in the article The effect of male circumcision on the sexual enjoyment of the
..... Click the link for more information.
The ridged band is part of the foreskin. John R. Taylor, a Canadian pathologist, medical researcher and opponent of circumcision, first described the ridged band at the Second International Symposium on Circumcision, organised by NOCIRC in San Francisco, 1991.
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