Clitoris

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Clitoris
Clitoris anatomy labeled-en.svg
The internal anatomy of the human vulva, with the clitoral hood and labia minora indicated as lines. The clitoris extends from the visible portion to a point below the pubic bone.
Gray's subject #270 1266
Artery Dorsal artery of clitoris, deep artery of clitoris
Vein Superficial dorsal veins of clitoris, deep dorsal vein of clitoris
Nerve Dorsal nerve of clitoris
Precursor Genital tubercle
MeSH Clitoris
Dorlands/Elsevier Clitoris

The clitoris (Listeni/ˈklɪtərɨs/, Listeni/klɨˈtɔərɨs/, or UK /ˈkltɒrɨs/) is a sexual organ that is present only in female mammals. In humans, the visible button-like portion is located near the anterior junction of the labia minora, above the opening of the urethra and vagina. Unlike the penis, which is homologous to the clitoris, the clitoris does not contain the distal portion of the urethra. The only known exception to this is in the Spotted Hyena. In this species, the urogenital system is unique in that the female urinates, mates and gives birth via an enlarged, erectile clitoris, known as a pseudo-penis.[1]

In humans, the clitoris is the most sensitive erogenous zone of the female and the primary cause of female sexual pleasure.[2][3][4][5] Capable of producing sexual excitement, clitoral erection and orgasm upon sexual stimulation, its size and sensitivity can vary and it has been the subject of extensive sociological, sexological and medical debate.[3][6][7][8]

Contents

Pronunciation and etymology

The plural forms are clitorises in English and clitorides in Latin. In slang, it is sometimes abbreviated as clit, which originated in the 1950s. The OED suggests that the pronunciation /ˈkltɒrɨs/ is also used in the United Kingdom, and gives the likely etymology as coming from the Greek κλειτορίς, kleitoris, perhaps derived from the verb κλείειν, kleiein, to shut. The Online Etymology Dictionary states that the etymology of this diminutive is uncertain. Possible etymological candidates are a Greek word meaning "key", "latch", "hook"; a Greek verb meaning "to touch or titillate lasciviously", "to tickle" (one German synonym for the clitoris is der Kitzler, “the tickler”), although this verb is more likely derived from "clitoris"; and a Greek word meaning "side of a hill", from the same root as "climax".[9] Its Latin genitive is clitoridis, as in "glans clitoridis".

Anatomy

Embryonic development

During the development of an embryo, at the time of development of the urinary and reproductive organs, the previously undifferentiated genital tubercle develops into either a clitoris or penis, along with all other major organ systems, making them homologous.[10] The clitoris is formed from the same tissues that would have become the glans and upper shaft of a penis if the embryo had been exposed to "male" hormones. Changes in appearance of male and female embryos begin roughly eight weeks after conception. By birth, the genital structures have developed into the female reproductive system.[11]

Embryo sex based on external genitalia is apparent to a doctor at the end of the 14th menstrual week, and the sex can usually be identified by an ultrasound after 16 to 18 menstrual weeks.[12] A condition that can develop from naturally occurring or deliberate exposure to higher than average levels of testosterone is clitoromegaly.

Structure

Human vulva
Vulva labeled no tags.jpg
Human vulva stretched to show externally-visible features of the clitoris in relation to other components: 1. Clitoral hood (prepuce); 2. Clitoral glans; 3. Urethral orifice; 4. Vulval vestibule; 5. Labia minora; 6. Vaginal opening; 7. Labia majora (hair removed); 8. Perineum
MeSH Vulva
Dorlands/Elsevier vulva

The head or glans of the clitoris is roughly the size and shape of a pea, although it can be significantly larger or smaller. The clitoris is a complex structure, with both external and internal components. Projecting at the front of the labial commissure where the edges of the outer lips (labia majora) meet at the base of the pubic mound is the clitoral hood (prepuce), which in full or part covers the head (clitoral glans). Following from the head back and up along the shaft, it is found that this extends up to several centimeters before reversing direction and branching. The resulting branched shape forms an inverted "V", extending as a pair of "legs" known as the clitoral crura formed of the corpora cavernosa. The clitoral crura are concealed behind the labia minora, and terminate with attachment to the pubic arch (according to some),[13] or follow interior to the labia minora to meet at the fourchette (according to others).[2]

Associated are the urethral sponge, clitoral/vestibular bulbs, perineal sponge, a network of nerves and blood vessels, suspensory ligaments, muscles and pelvic diaphragm.[10] The clitoris displays a hood that is the equivalent to the foreskin in men, which covers the glans, and a shaft that is attached to the glans.[10][14] The tip or glans of the clitoris alone has more than 8,000 sensory nerve endings,[14] more than the human penis or any other part of the human body.[14][15]

There is considerable variation in how much of the clitoris protrudes from the hood and how much is covered by it, ranging from complete, covered invisibility to full, protruding visibility. An article published in the Journal of Obstetrics and Gynecology in July 1992 states that the average width of the clitoral glans lies within the range of 2.5 to 4.5 millimetres (0.098 to 0.18 in), indicating that the average size is smaller than a pencil-top eraser. There is no identified correlation between the size of a clitoris and a woman's age, height, weight, use of hormonal contraceptives, or being post-menopausal. Recent discoveries about the size of the clitoris show that clitoral tissue extends considerably inside the vagina and that the vaginal walls may in fact be the clitoris, making the clitoris more prominent than the small visible part most people associate with the word.[3]

Findings and debates

Sexual stimulation

During sexual arousal and during orgasm, the clitoris and the whole of the genitalia engorge and change color as these erectile tissues fill with blood, and the individual experiences vaginal contractions. Masters and Johnson documented the sexual response cycle, which has four phases and is still the clinically accepted definition of the human orgasm. More recent research has determined that some can experience a sustained intense orgasm through stimulation of the clitoris and remain in the orgasmic phase for much longer than the original studies indicated, evidenced by genital engorgement, color changes, and vaginal contractions.[16]

Because the clitoris is homologous to the penis, it is the equivalent in its capacity to receive sexual stimulation.[10][14][17] Research into the female sexual response cycle demonstrates that most women (70-80%) achieve orgasm only through direct clitoral stimulation,[17][18][19][20] though indirect clitoral stimulation may also be sufficient.[3][20][21] Alfred Kinsey was the first to harshly criticize Sigmund Freud's theory that clitoral orgasms are a prepubertal or adolescent phenomenon and that vaginal (or G-Spot) orgasms are something that only physically mature females have.[4][8][22] Through his interviews with thousands of women,[23] Kinsey found that most women could not have vaginal orgasms.[4] He criticized Freud and other theorists for projecting male constructs of sexuality onto women and viewed the clitoris as the main center of sexual response and the vagina as relatively unimportant for sexual satisfaction, noting that few women inserted fingers or objects into their vaginas when they masturbated. Believing that vaginal orgasms are a physiological impossibility because the vagina has insufficient nerve endings for sexual pleasure or climax, he concluded that satisfaction from penile penetration is mainly psychological or perhaps the result of referred sensation.[4]

Masters and Johnson's research, as well as Shere Hite's, supported Kinsey's findings about the female orgasm.[4][6][7][21][24] Masters and Johnson were the first to determine that the clitoral structures surround and extend along and within the labia. They observed that both clitoral and vaginal orgasms had the same stages of physical response, and found that the majority of their subjects could only achieve clitoral orgasms, while a minority achieved vaginal orgasms. On this basis, they argued that clitoral stimulation is the source of both kinds of orgasms.[7][21] Supporting this conclusion is a 2005 study which investigated the size of the clitoris; Australian urologist Dr. Helen O'Connell, while using MRI technology, noted a direct relationship between the legs or roots of the clitoris and the erectile tissue of the clitoral bulbs and corpora, and the distal urethra and vagina. While some studies, using ultrasound, have found physiological evidence of the G-Spot in women who report having orgasms during intercourse,[25][26] O'Connell asserts that this interconnected relationship is the physiological explanation for the conjectured G-Spot and experience of vaginal orgasms, taking into account the stimulation of the internal parts of the clitoris during vaginal penetration.[3] "The vaginal wall is, in fact, the clitoris," said O'Connell. "If you lift the skin off the vagina on the side walls, you get the bulbs of the clitoris – triangular, crescental masses of erectile tissue." O'Connell and her team were already aware that the clitoris is more than just its glans – the "little hill". They reasoned that it is possible that some women have more extensive clitoral tissues and nerves than others, and therefore whereas many women can only achieve orgasm by direct stimulation of the external parts of the clitoris, for others the stimulation of the more generalized tissues of the clitoris via intercourse may be sufficient.[3]

Masters and Johnson's research came at the time of the second-wave feminist movement, which inspired feminists to reject the distinction made between clitoral and vaginal orgasms. "Men have orgasms essentially by friction with the vagina, not the clitoral area, which is external and not able to cause friction the way penetration does. Women have thus been defined sexually in terms of what pleases men; our own biology has not been properly analyzed," stated feminist Anne Koedt in her 1970 article The Myth of the Vaginal Orgasm. "Today, with extensive knowledge of anatomy, with [C. Lombard Kelly], Kinsey, and Masters and Johnson, to mention just a few sources, there is no ignorance on the subject [of the female orgasm]. There are, however, social reasons why this knowledge has not been popularized. We are living in a male society which has not sought change in women's role."[8]

Whether or not the clitoris is vestigial or serves a reproductive function has also been subject to debate.[20] At the 2002 conference for Canadian Society of Women in Philosophy, Dr. Nancy Tuana asserted that the clitoris is unnecessary in reproduction, but that this is why it has been "historically ignored," mainly because of "a fear of pleasure. It is pleasure separated from reproduction. That's the fear". She reasoned that this fear is the cause of the ignorance that veils female sexuality.[7] O'Connell said, "It boils down to rivalry between the sexes: the idea that one sex is sexual and the other reproductive. The truth is that both are sexual and both are reproductive."[3] She reiterates that the bulbs appear to be part of the clitoris and that the distal urethra and vagina are intimately related structures, although they are not erectile in character, forming a tissue cluster with the clitoris that appears to be the locus of female sexual function and orgasm.[3]

Pulled-out clitoral glans

Existence and accuracy in illustrations

The clitoris has been thought of as "discovered" and "rediscovered" through empirical documentation by male scholars repeatedly over the centuries.[27][28] Over a period of more than 2,500 years, some have considered the clitoris and the penis equivalent in all respects except their arrangement.[2] Realdo Colombo (also known as Matteo Renaldo Colombo) was a lecturer in surgery at the University of Padua, Italy, and in 1559 he published a book called De re anatomica[29] in which he described the "seat of woman's delight". In his role as researcher, Colombo concluded, "Since no one has discerned these projections and their workings, if it is permissible to give names to things discovered by me, it should be called the love or sweetness of Venus."[30]

Colombo's claim was disputed by his successor at Padua, Gabriele Falloppio (who discovered the fallopian tube), who claimed that he was the first to discover the clitoris. Caspar Bartholin, a 17th-century Danish anatomist, dismissed both claims, arguing that the clitoris had been widely known to medical science since the second century. Indeed, Hippocrates used the term columella (little pillar). Avicenna named the clitoris the albatra or virga (rod). Albucasis, an Arabic medical authority, named it tentigo (tension). It was also known to the Romans, who named it (vulgar slang) landica.[31]

This cycle of suppression and discovery continued, notably in the work of Regnier de Graaf in the 17th century[32] and Georg Ludwig Kobelt in the 19th.[3][33] De Graaf criticised Columbo's claims for this.[27][28] O'Connell describes typical textbook descriptions of the clitoris as lacking detail and including inaccuracies, and credits the work of Georg Ludwig Kobelt with providing a most comprehensive and accurate description of clitoral anatomy.[3] The full extent of the clitoris was additionally alluded to by Masters and Johnson in 1966, but in such a muddled fashion that the significance of their description became obscured. In 1981, the Federation of Feminist Women's Health Clinics (FFWHC) continued this process with anatomically precise illustrations.[2] Today, MRI complements these efforts, as it is both a live and multi-planar method of examination.[3]

Modification and mutilation

The clitoris may be partially or totally removed during female genital mutilation (FGM), also known as a clitoridectomy, or female circumcision. This is carried out in several countries in Africa, and to a lesser extent in the Middle East and Southeast Asia, on girls from a few days old to the age of 15.[34] Amnesty International estimates that over two million FGM procedures are performed every year.[35] Removing the glans of the clitoris does not mean that the whole structure is lost, since the clitoris reaches deep into areas of the genitals.[3]

In various cultures, the clitoris is sometimes pierced directly. In U.S. body modification culture, it is actually extremely rare for the clitoral shaft itself to be pierced, as of the already few people who desire the piercing, only a small percentage are anatomically suited for it; furthermore, most piercing artists are reluctant to attempt such a delicate procedure. Some styles, such as the Isabella, do pass through the clitoris but are placed deep at the base, where they provide unique stimulation; they still require the proper genital build, but are more common than shaft piercings. Additionally, what is referred to as a "clit piercing" is almost always the much more common (and much less complicated) clitoral hood piercing.

Enlargement may be intentional or unintentional. Those taking hormones and/or other medications as part of female-to-male transition usually experience dramatic clitoral growth; individual desires (and the difficulties of surgical phalloplasty) often result in the retention of the original genitalia, the enlarged clitoris analogous to a penis as part of the transition. However, the clitoris cannot reach the size of most cissexual men's penises through hormones. Surgery to add function to the clitoris, such as metoidioplasty or clitoral release, are alternatives to phalloplasty (construction of a penis) which permit retention of sexual sensation in the clitoris.

On the other hand, use of anabolic steroids by bodybuilders and other athletes can result in significant enlargement of the clitoris in concert with other masculinizing effects on their bodies. Temporary engorgement results from suction pumping, practiced to enhance sexual pleasure or for aesthetic purposes.

Additional images

See also

References

  1. ^ Baskina, Laurence S. et al. (January 2006). "A Neuroanatomical Comparison of Humans and Spotted Hyena, a Natural Animal Model for Common Urogenital Sinus: Clinical Reflections on Feminizing Genitoplasty". Journal of Urology 175 (1): 276–83. doi:10.1016/S0022-5347(05)00014-5. PMID 16406926. 
  2. ^ a b c d Chalker, Rebecca (2000). The Clitoral Truth. Seven Seas Press. p. 1. ISBN 1-58322-473-4. http://www.sevenstories.com/Book/index.cfm?GCOI=58322100427350. 
  3. ^ a b c d e f g h i j k l O'Connell HE, Sanjeevan KV, Hutson JM (October 2005). "Anatomy of the clitoris". The Journal of Urology 174 (4 Pt 1): 1189–95. doi:10.1097/01.ju.0000173639.38898.cd. PMID 16145367. Time for rethink on the clitoris: Lay summary – BBC News (11 June 2006). 
  4. ^ a b c d e Janice M. Irvine (2005). Disorders of desire: sexuality and gender in modern American sexology. Temple University Press. pp. 304 pages. ISBN 1592131514, 9781592131518. http://books.google.com/books?id=uIJXT7ZCTCsC&pg=PA37&dq=Kinsey+criticized+Freud&hl=en&sa=X&ei=jFADT5u0KKWo2wXY9pSeAg&ved=0CD4Q6AEwAg#v=onepage&q=Kinsey%20criticized%20Freud&f=false. Retrieved January 3, 2012. 
  5. ^ Wayne Weiten, Dana S. Dunn, Elizabeth Yost Hammer (2011). Psychology Applied to Modern Life: Adjustment in the 21st Century. Cengage Learning. pp. 688 pages. ISBN 1111186634, 9781111186630. http://books.google.com/books?id=CGu96TeAZo0C&pg=PT423&dq=&hl=en&sa=X&ei=MwIGT-jxEojU2AWzv5ylCg&ved=0CDwQ6AEwAA#v=onepage&q=false. Retrieved January 5, 2012. 
  6. ^ a b Shere Hite: "I was making the point that clitoral stimulation wasn't happening during coitus. That's why women 'have difficulty having orgasms' - they don't have difficulty when they stimulate themselves.
    Tracey Cox: "It's disappointing that one of Hite's main messages - that 70 per cent of women don't have orgasms through penetration - is not completely accepted today. Plenty of women don't feel comfortable admitting it, even to themselves, for fear their partners will love them less. But women are far more experimental now." "Shere Hite: On female sexuality in the 21st century". The Independent. April 30, 2006. http://www.independent.co.uk/news/people/profiles/shere-hite-on-female-sexuality-in-the-21st-century-475981.html. Retrieved April 10, 2011. 
  7. ^ a b c d Cairney, Richard (October 21, 2002). "Exploring female sexuality". ExpressNews. Archived from the original on June 29, 2011. http://liveweb.archive.org/http://www.archives.expressnews.ualberta.ca/article/2002/10/3201.html. Retrieved December 21, 2011. 
  8. ^ a b c Koedt, Anne (1970). "The Myth of the Vaginal Orgasm". Chicago Women's Liberation Union (CWLU). http://www.uic.edu/orgs/cwluherstory/CWLUArchive/vaginalmyth.html. Retrieved December 12, 2011. 
  9. ^ Harper, Douglas. "clitoris". Online Etymology Dictionary. http://www.etymonline.com/index.php?term=clitoris. 
  10. ^ a b c d Francoeur, Robert T. (2000). The Complete Dictionary of Sexology. The Continuum Publishing Company. p. 180. ISBN 0-82640-672-6. 
  11. ^ Reinisch, Beasley, June and Ruth (1990). The Kinsey Institute New Report on Sex. St. Martin’s Press. ISBN 0312063865. 
  12. ^ Heffner, Linda (2001). Human Reproduction at a Glance. Blackwell Sciences, Ltd. ISBN 0632054611. 
  13. ^ Vulva on MedicaLook Human Anatomy
  14. ^ a b c d Cornforth, Tracee (17 July 2009). "The Clitoral Truth. Interview with author and sex educator Rebecca Chalker.". About.com. http://womenshealth.about.com/cs/sexuality/a/clitoraltruthin.htm. Retrieved 21 April 2010. 
  15. ^ "I'm a woman who cannot feel pleasurable sensations during intercourse". Go Ask Alice!. October 08, 2004 (Last Updated/Reviewed on October 17, 2008). http://www.goaskalice.columbia.edu/3229.html. Retrieved November 19, 2011. 
  16. ^ Bodansky, Vera & Steve (2002). The Illustrated Guide to Extended Massive Orgasm. Hunter House. ISBN 0897933621. 
  17. ^ a b "'I Want a Better Orgasm!'". WebMD. Archived from the original on 2009-01-13. http://web.archive.org/web/20090113132443/http://www.webmd.com/sex/want-better-orgasms. Retrieved August 18, 2011. 
  18. ^ Jeffrey Weeks (1985). Sexuality and its discontents: meanings, myths, & modern sexualities. Psychology Press. pp. 324 pages. ISBN 0415045037, 9780415045032. http://books.google.com/books?id=QzkTiK9oQVIC&pg=PA89&dq=&hl=en&sa=X&ei=cv4FT_bSFeu62gXp8KyKAg&ved=0CEQQ6AEwAQ#v=onepage&q=false. Retrieved January 5, 2012. 
  19. ^ "The amount of time of sexual arousal needed to reach orgasm is variable — and usually much longer — in women than in men; thus, only 20-30% of women attain a coital climax. b. Many women (70-80%) require manual clitoral stimulation..." Joseph A. Flaherty, John Marcell Davis, Philip G. Janicak (1993, Digitized Oct 29, 2010). Psychiatry: Diagnosis & therapy. A Lange clinical manual. Appleton & Lange (Original from Northwestern University). pp. 544 pages. ISBN 0838512674, 9780838512678. https://www.google.com/search?hl=en&noj=1&biw=1024&bih=629&tbm=bks&q=The+amount+of+time+of+sexual+arousal+needed+to+reach+orgasm+is+variable+%E2%80%94+and+usually+much+longer+%E2%80%94+in+women+than+in+men%3B+thus%2C+only+20-30%25+of+women+attain+a+coital+climax.+b.+Many+women+%2870-80%25%29+require+manual+clitoral+stimulation.&btnG=Search&oq=The+amount+of+time+of+sexual+arousal+needed+to+reach+orgasm+is+variable+%E2%80%94+and+usually+much+longer+%E2%80%94+in+women+than+in+men%3B+thus%2C+only+20-30%25+of+women+attain+a+coital+climax.+b.+Many+women+%2870-80%25%29+require+manual+clitoral+stimulation.&aq=f&aqi=&aql=&gs_sm=s&gs_upl=2326483l2326991l0l2328690l1l1l0l0l0l0l0l0ll0l0. Retrieved January 5, 2012. 
  20. ^ a b c Elisabeth Anne Lloyd (2005). The case of the female orgasm: bias in the science of evolution. Harvard University Press. pp. 311 pages. ISBN 0674017064, 9780674017061. http://books.google.com/books?id=6GFNvA6TvlwC&pg=PA53&dq=en&sa=X&ei=Jg0GT_3QNoqQ2QWL-KSBCg&ved=0CEMQ6AEwADgo#v=onepage&q=false. Retrieved January 5, 2012. 
  21. ^ a b c Federation of Feminist Women’s Health Centers (1991). A New View of a Woman’s Body. Feminist Heath Press. p. 46. ISBN 0-9629945-0-2. 
  22. ^ "Difference between clitoral and vaginal orgasm". Go Ask Alice!. December 23, 1994 (Last Updated/Reviewed on March 28, 2008). http://www.goaskalice.columbia.edu/0469.html. Retrieved April 21, 2010. 
  23. ^ Margaret L. Andersen, Howard Francis Taylor (2007). Sociology: understanding a diverse society. Cengage Learning. pp. 151 pages. ISBN 0495007420, 9780495007425. http://books.google.com/books?id=UILcQZS6Bi4C&pg=PA338&dq=Kinsey+criticized+Freud&hl=en&sa=X&ei=jFADT5u0KKWo2wXY9pSeAg&ved=0CDcQ6AEwAQ#v=onepage&q=Kinsey%20criticized%20Freud&f=false. Retrieved January 3, 2012. 
  24. ^ "The Hite Reports: What do they say?". hite-research.com. Archived from the original on June 1, 2009. http://web.archive.org/web/20090601230726/http://www.hite-research.com/thehitereports.htm. Retrieved November 19, 2011. 
  25. ^ "Finding the G-spot: Is it real?". CNN.com. January, 05, 2010. http://www.cnn.com/2010/HEALTH/01/05/g.spot.sex.women/index.html. Retrieved November 7, 2011. 
  26. ^ Gravina GL, Brandetti F, Martini P, et al. (2008). "Measurement of the Thickness of the Urethrovaginal Space in Women with or without Vaginal Orgasm". J Sex Med 5 (3): 610. doi:10.1111/j.1743-6109.2007.00739.x. PMID 18221286. 
  27. ^ a b Laqueur, T. W. (1989) "Amor Veneris, vel Dulcedo Appeletur", in Fragments for a History of the Human Body. No.3 Feher, M., Naddaff, R., Tazi, N. (eds.) New York: Zone; pp. 91–131
  28. ^ a b Harvey, E. (2002) "Anatomies of Rapture: clitoral politics/medical blazons", Signs 27(2) Winter 2002, pp. 315–46
  29. ^ Realdi Columbi Cremonensis, De re anatomica, libri XV. Venetiis: Ex typographia Nicolai Beuilacquæ, 1559.
  30. ^ "Hos igitur processus, atque eorundem usum cum nemo hactenus animadverterit, si nomina rebus a me inventis imponere licet, amor Veneris, vel dulcedo appeletur." Realdo Colombo, De re anatomica, 1562. Old Latin version in Google Books.
  31. ^ J.N. Adams (1982). The Latin Sexual Vocabulary. Johns Hopkins University Press. pp. 97–98. 
  32. ^ (Tractatus de Virorum Organis Generationi Inservientibus, De Mulierum Organis Generationi Inservientibus Tractatus Novus)
  33. ^ (Die männlichen und weiblichen Wollustorgane des Menschen und einiger Säugetiere)
  34. ^ Momoh, Comfort. "Female Genital Mutilation", Radcliffe Publishing, 2005, pp. 5–9.
  35. ^ <Please add first missing authors to populate metadata.> (30). "What is Female Genital Mutilation?". Amnesty International: 2. doi:ACT77/06/97. http://www.Amnesty.org/en. Retrieved 25 April 2010. 

External links

Media related to Clitoris at Wikimedia Commons

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