giovedì 13 ottobre 2011

Circumcision Sexual Dysfunction

Foreskin Sexual Function/Circumcision Sexual Dysfunction

The human foreskin is highly innervated,5 21 29 and vascularized29 sensitive erogenous tissue.6 29 It plays an important role in normal human sexual response and is necessary for normal copulatory behavior.40 An understanding of this role is now emerging in the scientific literature. Removal of the foreskin (circumcision) interferes with normal sexual function.

This page brings together, in one place, scattered material relevant to the study of the role of the foreskin in human sexuality, and the dysfunction caused by its amputation.

Summary of the literature
Protection. The foreskin in the adult male either partially or completely covers the glans penis.40 The foreskin protects the glans penis from friction and from dryness.28 The foreskin maintains the sub-preputial space in a state of wetness with prostatic, vesicular and urethral secretions.17 The glans penis is covered with mucosa, not skin, so the wetness is essential for optimum health. There may be a correlation between wetness and sensitivity. Removal of the prepuce by circumcision results in a change in the appearance of the glans penis. The color tends to change from a red-purple to a light pink in caucausians and the texture changes from a glossy finish to a matte finish and becomes dull rather than shiny. Some believe that the epithelium of the glans thickens after removal of the foreskin to provide additional layers of protection and that this keratinization deadens sensation.10 Morgan (1965) said, "Removal of the prepuce exposes the glans to foreign stimuli which dull these special receptors.11 Bigelow (1994) observed that improvement in glanular sensitivity is the most frequently reported outcome of foreskin restoration.26 Pertot (1994) reports that the glans becomes softer after foreskin restoration.27 These older papers do not recognize the sensitivity of the foreskin itself.

Some doctors who are associated with the Albert Einstein College of Medicine at Yeshiva University have carried out measurements of glanular sensitivity in both circumcised and intact males.53 54 Bleustein et al. (2003) claimed to measure overall penile sensitivity, but their methodology made that impossible. Even though the high innervation,6 21 29 40 the sensitivity,12 39 51 and the erogenous nature,6 of the foreskin had been reported previously, the foreskin inexplicably was not tested. The foreskin was held back out of the way53 54 and the contribution of the foreskin to overall penile sensitivity was not determined. Their studies reported little difference in glanular sensitivity between circumcised and intact males.53 54 If that is the case, then the decrease in penile sensitivity after circumcision and the increase noted after foreskin restoration must lie elsewhere.57 The most likely location is in the foreskin.57 Denniston reported loss of sexual pleasure in a survey of males circumcised in adulthood.61 The most recent study finds that the intact penis is about four times more sensitive than the circumcised penis.67

Mechanical function. The foreskin provides mechanical functions to facilitate intromission and penetration. Several authorities observe that the penis enters the vagina without friction as the foreskin unfolds.4 9 10 11 Taves (2002) reported that excision of the foreskin by circumcision increases the force required to penetrate by ten-fold.51 Shen et al. reported 43.1 percent of men cirumcised as adults experience difficult penetration.59 After penetration, the foreskin provides a gliding action that greatly reduces friction,4 9 11 15 41 49and vaginal dryness.27 40 50 55

Elasticity. The foreskin has a layer of smooth muscle tissue called the peripenic muscle,1 which is part of the dartos muscle.1 39 The contraction and expansion of the muscle fibers in this layer give the foreskin great elasticity and are important in erogenous sensation. Lakshmanan & Prakash report a "mosaic of muscle tissues and elastic fibres" contained between the two layers of the foreskin, which keep the foreskin snugly against in the glans penis in a close fit.15 The muscle fibres must stretch to allow the foreskin to retract over the glans and contract again when the foreskin returns to its normal forward position. The expansion and contraction of the muscle fibres during coitus allows the foreskin to stretch. The stretching deformes the Meissner corpuscles and produces sensation.68 The nerve bundles run alongside the dartos muscle.40 The stretching puts tension on the nerve endings contained within the foreskin. The nerve endings deform and generate pleasurable erotic sensations to the central nervous system and inputs to the autonomic nervous system, which plays a role in controlling erection and ejaculation.57 68 Taylor (2003) reports preliminary evidence that stretching of the foreskin produces contractions associated with ejaculation.58 Taylor reports that the ridged band of the foreskin is reflexogenic and produces contractions that result in ejaculation.68

Erogenous tissue. the foreskin is heavily innervated even at birth and before.5 21 The foreskin is a specific erogenous zone6 with nerve endings near the surface of the ridged band arranged in rete ridges.29 The foreskin is noted for its sensory pleasure.12 36 51 Circumcision, therefore, diminishes sexual sensation.6 9 10 11 12 18 28 31 38 57 59 62 63 64

Impotence and sexual dysfunction. The nerves in the foreskin apparently provide an impulse to aid erection. Circumcision has long been associated with an increased incidence of impotence. Glover (1929) reported a case.2 Winkelmann (1959) suggested impotence as a possibility,6 as did Foley (1966).10 Stinson (1973) reported five cases.13 Palmer & Link (1979) reported two cases.14 More recently, additional evidence of sexual dysfunction after circumcision has emerged. Coursey et al. reported that the degradation in sexual function after circumcision is equivalent to the degradation experienced after anterior urethroplasty.47 Fink et al. reported statistically significant degradation in sexual function.49 A survey carried out in South Korea found that circumcised men reported painful erections, and diminished sexual pleasure, and a few reported curvature of the penis upon erection.48 Shen et al. (2004), in a study carried out in China, reported erectile dysfunction in 28.4 percent of the men in the study after circumcision, and 'weakened erectile confidence' in 34.7 percent.59

Premature ejaculation. Lakshmanan & Prakash (1980) report that the foreskin impinges against the corona glandis during coitus.15 The foreskin, therefore, tends to protect the corona glandis from direct stimulation by the vagina of the female partner during coitus. The corona is the most highly innervated part of the glans penis.19 Zwang argues that removal of the foreskin allows direct stimulation of the corona glandis and this may cause premature ejaculation in some males.32 O'Hara & O'Hara (1999) report more premature ejaculation in circumcised male partners.41 The presence of the foreskin, therefore, may make it easier to avoid premature ejaculation, while its absence would make it more difficult to avoid premature ejaculation. Masood et al. report that circumcision is more likely to worsen premature ejaculation than improve it.64 The Australian Study of Health and Relationships found that "26% of circumcised men but 22% of uncircumcised men reported reaching orgasm too quickly for at least one month in the previous year."65 Kim & Pang (2006) reported decreased ejaculation latency time in circumcised men but the decrease was not considered statistically significant.66

Inability to ejaculate or delayed ejaculation. While some circumcised males may suffer from a tendency toward premature ejaculation, others find that they have great difficulty in ejaculating.50 The nerves in the foreskin and ridged band are stimulated by stretching,18 57 amongst other movements. If those nerves are not present, Money (1983) argues that excision of these stretch receptors by circumcision may make ejaculation take longer.18. Some circumcised males may have to resort to prolonged and aggressive thrusting to achieve orgasm.40 49 Shen et al. (2004) reported that 32.6 percent of the men in his study reported prolonged intercourse after circumcision.59 Senkul et al. (2004) reported an appreciable increase in ejaculatory latency time (time to ejaculate).60 Thorvaldsen & Meyhoff (2005) reported that circumcised males have more difficulty with ejaculation and orgasm.63 Kim & Pang (2006) reported that circumcised men have more difficulty with masturbation.66 Solinis & Yiannaki reported that 65 percent of circumcised men in their study reported increased ejaculation time in their study.69

Loss of sexual pleasure. Denniston reported that some circumcised men would not have the operation again because of loss of sexual pleasure.61 Kim & Pang (2006) reported that 48 percent of Korean men in a survey experienced loss of mastubatory pleasure after circumcision as compared with 8 percent that experienced increased pleasure and 8 percent reported improved sexual life, but 20 percent reported worsened sexual life.66 Solinis & Yiannaki reported that 16 percent of the men in their study reported a better sex life after circumcision but 35 percent reported a worsened sex life.69

Sexual behaviour. The alteration to the sexual organ causes many circumcised males to change their sexual behavior. Foley reported that circumcised males are more likely to masturbate.10 Hooykaas et al. (1991) reported that immigrant (mostly circumcised) males have a greater tendency to engage in risky sexual behavior with prostitutes as compared with Dutch (mostly normal intact) males.23 The U. S. National Health and Social Life Survey found that circumcised males have a "more elaborated" set of sexual practices, including more masturbation, and more heterosexual oral sex.30 The British National Survey of Sexual Attitudes and Lifestyles (2000) reported that circumcised males were more likely to report having a homosexual partner and more likely to have partners from abroad as compared with normal intact males.56 Circumcised men are significantly less likely to use condoms.38 50 Many men in the Solinis and Yiannaki study reported decreased sex life after circumcision.69

Value to female partners. The foreskin has long been known to be valuable to the female partner.8 16 The presence of the foreskin is reported to be stimulating to the female.41 45 55 Women are more likely to experience vaginal dryness during sex with a circumcised partner.24 28 62 The unnatural dryness may make coitus painful and result in abrasions.28 41 50 The vaginal dryness may be mistakenly attributed to female arousal disorder.55 62 O'Hara & O'Hara report that the female partner is less likely to experience orgasm when the foreskin is not present and more likely to experience orgasm or even multiple orgasms when the foreskin is present.41 Solinis & Yiannaki found that 46 percent of men in their study reported a worsened sex life for their partner while 33 percent reported that that their partner's sex life had improved.69

One should also see Circumcision and Sexuality. (link to www.circumstitions.com)