Vagina

Vagina
Human vagina; normal canal (left) and canal during menopause (right)
Diagram of the female human reproductive tract and ovaries
Details
Precursor	Urogenital sinus and paramesonephric ducts
Artery	Superior part to uterine artery, middle and inferior parts to vaginal artery
Vein	Uterovaginal venous plexus, vaginal vein
Nerve	Sympathetic: lumbar splanchnic plexus Parasympathetic: pelvic splanchnic plexus
Lymph	Upper part to internal iliac lymph nodes, lower part to superficial inguinal lymph nodes
Identifiers
Latin	vagina
MeSH	D014621
TA98	A09.1.04.001
TA2	3523
FMA	19949
Anatomical terminology [edit on Wikidata]

In mammals and other animals, the vagina (pl.: vaginas or vaginae)^[1] is the elastic, muscular reproductive organ of the female genital tract. In humans, it extends from the vestibule to the cervix. The outer vaginal opening is normally partly covered by a thin layer of mucosal tissue called the hymen. At the deep end, the cervix (neck of the uterus) bulges into the vagina. The vagina allows for copulation and birth. It also channels menstrual flow, which occurs in humans and closely related primates as part of the menstrual cycle.

Although research on the vagina is especially lacking for different animals, its location, structure and size are documented as varying among species. Female mammals usually have two external openings in the vulva; these are the urethral opening for the urinary tract and the vaginal opening for the genital tract. This is different from male mammals, who usually have a single urethral opening for both urination and reproduction. The vaginal opening is much larger than the nearby urethral opening, and both are protected by the labia in humans. In amphibians, birds, reptiles and monotremes, the cloaca is the single external opening for the gastrointestinal, urinary, and reproductive tracts.

To accommodate smoother penetration of the vagina during sexual intercourse or other sexual activity, vaginal moisture increases during sexual arousal in human females and other female mammals. This increase in moisture provides vaginal lubrication, which reduces friction. The texture of the vaginal walls creates friction for the penis during sexual intercourse and stimulates it toward ejaculation, enabling fertilization. Along with pleasure and bonding, women's sexual behavior with others (which can include heterosexual or lesbian sexual activity) can result in sexually transmitted infections (STIs), the risk of which can be reduced by recommended safe sex practices. Other health issues may also affect the human vagina.

The vagina and vulva have evoked strong reactions in societies throughout history, including negative perceptions and language, cultural taboos, and their use as symbols for female sexuality, spirituality, or regeneration of life. In common speech, the word vagina is often used incorrectly to refer to the vulva or to the female genitals in general.