Vagina

Un article de Vev.

Modèle:Pp-semi-protected Modèle:Otheruses Modèle:Infobox Anatomy The vagina, (from Latin, literally "sheath" or "scabbard" ) is the tubular tract leading from the uterus to the exterior of the body in female placental mammals and marsupials, or to the cloaca in female birds, monotremes, and some reptiles. Female insects and other invertebrates also have a vagina, which is the terminal part of the oviduct. The Latinate plural (rarely used in English) is vaginae.

In common speech, the term "vagina" is often used to refer to the vulva or female genitals generally; strictly speaking, the vagina is a specific internal structure and the vulva is the exterior genitalia only.

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Human anatomy

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Unstretched human vulva showing vaginal opening.

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Stretched human vulva showing stretched vaginal opening.

The human vagina is an elastic muscular canal that extends from the cervix to the vulva.<ref>http://www.womenshealth.gov/glossary/#vagina Womenshealth.gov </ref> Although there is wide anatomical variation, the length of the unaroused vagina is approximately 6 to 7.5 cm (2.5 to 3 in) across the anterior wall (front), and 9 cm (3.5 in) long across the posterior wall (rear).<ref>Gray's Anatomy</ref> During sexual arousal the vagina expands in both length and width.<ref> The sexual response cycle

. EngenderHealth

. Retrieved on 2007-10-13. </ref> Its elasticity allows it to stretch during sexual intercourse and during birth to offspring.<ref>http://www.metrokc.gov/HEALTH/famplan/flash/grades11-12/G1112-L17.pdf Metrokc.gov</ref> The vagina connects the superficial vulva to the cervix of the deep uterus.

If the woman stands upright, the vaginal tube points in an upward-backward direction and forms an angle of slightly more than 45 degrees with the uterus. The vaginal opening is at the caudal end of the vulva, behind the opening of the urethra. Above the vagina is Mons Veneris. The vagina, along with the inside of the vulva, is reddish pink in color, as with most healthy internal mucous membranes in mammals.

Vaginal lubrication is provided by the Bartholin's glands near the vaginal opening and the cervix. The membrane of the vaginal wall also produces moisture, although it does not contain any glands. Before and during ovulation, the cervix produces cervical mucus, which provides a favorable environment for sperm to survive.

The hymen is a membrane which is situated at the opening of the vagina. As with many female animals, the hymen covers the opening of the vagina from birth until it is ruptured during activity. The hymen may rupture during sexual or non-sexual activity. Vaginal penetration may rupture the hymen. A pelvic examination, injury, or certain types of exercises, such as horseback riding or gymnastics may also rupture the hymen. Sexual intercourse does not always rupture the hymen.<ref>Modèle:Cite journal</ref> Therefore, the presence or absence of a hymen does not indicate virginity or prior sexual activity.

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Biological functions of the vagina

The vagina has several biological functions.

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Menstruation

The vagina provides a path for menstrual blood and tissue to leave the body. In industrial societies, tampons, menstrual cups and sanitary towels may be used to absorb or capture these fluids.

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Sexual activity

The concentration of the nerve endings that lie close to the entrance of a woman's vagina can provide pleasurable sensation during sexual activity, when stimulated in a way that the particular woman enjoys. During sexual arousal and particularly stimulation of the clitoris, the walls of the vagina self-lubricate, reducing friction during sexual activity. Research has found that portions of the clitoris extend into the vulva and vagina.<ref>Mascall, Sharon, “Time for Rethink on the Clitoris”, BBC News. 2006 June |url=http://news.bbc.co.uk/1/hi/health/5013866.stm</ref>

With arousal, the vagina lengthens rapidly to an average of about 4 in.(8.5 cm), but can continue to lengthen in response to pressure.<ref> Does size matter

. TheSite.org

. Retrieved on 2006-08-12. </ref> As the woman becomes fully aroused, the vagina tents (last ²⁄₃ expands in length and width) while the cervix retracts.<ref> do big penises hurt?

. AskMen.com

. Retrieved on 2006-08-14. </ref> The walls of the vagina are composed of soft elastic folds of mucous membrane skin which stretch or contract (with support from pelvic muscles) to the size of the penis. With proper arousal, the vagina may stretch/contract to accommodate virtually any penis size (or sex toy/object within reason).<ref> The female reproductive system

. birth.com.au

. Retrieved on 2007-05-07. </ref><ref> Facts about penis size

. netdoctor.co.uk

. Retrieved on 2007-05-14. </ref>

An erogenous zone referred to commonly as the G-spot is located at the anterior wall of the vagina, about five centimeters in from the entrance. Some women experience intense pleasure if the G-spot is stimulated appropriately during sexual activity. A G-Spot orgasm may be responsible for female ejaculation, leading some doctors and researchers to believe that G-spot pleasure comes from the Skene's glands, a female homologue of the prostate, rather than any particular spot on the vaginal wall.<ref>Modèle:Cite book</ref><ref>Modèle:Cite journal</ref><ref>Modèle:Cite journal</ref> Some researchers deny the existence of the G-spot.<ref name=Hines> Modèle:Cite journal</ref>

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Childbirth

During childbirth, the vagina provides the route to deliver the baby from the uterus to its independent life outside the body of the mother. During birth, the vagina is often referred to as the birth canal. The vagina is remarkably elastic and stretches to many times its normal diameter during vaginal birth.

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Sexual health and hygiene

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This section does not cite any references or sources.
Please improve this section by adding citations to reliable sources. Unverifiable material may be challenged and removed. (December 2007)

Main article: vulvovaginal health

The vagina is a self-cleaning organ and needs no special treatment. Doctors discourage douching, which upsets the balance of vaginal flora, and may cause infection, including PID, or other problems. Betty Dodson addresses the self-consciousness that many women feel about the scent or flavor of their vaginal fluids in her writings, and encourages women to accept their bodies as normal and natural.

The vagina is examined during gynecological exams, often using a speculum, which holds the vagina open for visual inspection of the cervix or taking of samples (see pap smear).

Vulvovaginal disorders can affect the vagina, including vaginal cancer and yeast infections, as well as sexually transmitted infections.

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The vagina and popular culture

The Vagina Monologues.

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Additional images

Uterus and uterine tubes.	Organs of the female reproductive system.	Schematic vulva anatomy.	Uterus and right broad ligament, seen from behind.
Sagittal section of the lower part of a female trunk, right segment.	Posterior half of uterus and upper part of vagina.	Layers of the vaginal wall.	Image showing stretched vulva with surrounding.