| Clitoris | |
|---|---|
| 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 (i/ˈklɪtərɨs/, i/klɨˈtɔərɨs/, or UK /ˈklaɪtɒrɨs/) 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] 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][5][6][7]
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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 /ˈklaɪtɒrɨs/ 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".[8] Its Latin genitive is clitoridis, as in "glans clitoridis".
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.[9] 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.[10]
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.[11] A condition that can develop from naturally occurring or deliberate exposure to higher than average levels of testosterone is clitoromegaly.
The head or glans of the clitoris is roughly the size and shape of a pea, although it can be significantly larger or smaller.
| Human vulva | |
|---|---|
| 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 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),[12] 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.[9] 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, etc.[9][13] The tip or glans of the clitoris alone has more than 8,000 sensory nerve endings,[13] more than the human penis or any other part of the human body.[13][14]
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]
Because the clitoris is homologous to the penis, it is the equivalent in its capacity to receive sexual stimulation.[9][13][15] 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]
Research into the female sexual response cycle and anatomy demonstrates that most women (70-80%) achieve orgasm only through direct clitoral stimulation, though indirect clitoral stimulation may also be sufficient.[3][15][17][18] Alfred Kinsey was the first to harshly criticize Sigmund Freud's theory that clitoral orgasms are an adolescent phenomenon and that vaginal (or G-Spot) orgasms are something that only physically mature women have.[4][7][19] Through his interviews with thousands of women,[20] 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 was mainly psychological or perhaps the result of referred sensation.[4]
Masters and Johnson's research into the sexual response cycle supported Kinsey's findings about the female orgasm.[4][6][17] 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.[6][17] Shere Hite's research also found that most women achieve clitoral orgasms.[5][21]
Supporting Masters and Johnson's 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. 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]
The clitoris has been thought of as "discovered" and "rediscovered" through empirical documentation by male scholars repeatedly over the centuries.[22] 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[23] 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."[24]
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.[25]
This cycle of suppression and discovery continued, notably in the work of Regnier de Graaf (Tractatus de Virorum Organis Generationi Inservientibus, De Mulierum Organis Generationi Inservientibus Tractatus Novus) in the 17th century and Georg Ludwig Kobelt (Die männlichen und weiblichen Wollustorgane des Menschen und einiger Säugetiere) in the 19th. De Graaf criticised Columbo's claims for this. (Harvey, Laqueur).
The full extent of the clitoris was 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 multiplanar method of examination.[3]
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.[26] Amnesty International estimates that over two million FGM procedures are performed every year.[27] Removing the glans of the clitoris does not mean that the whole structure is lost, since it 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.
Media related to [//commons.wikimedia.org/wiki/Category:Clitoris Clitoris] at Wikimedia Commons
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