vagina

vagina {vəjinə}
noun (pl. vaginas or vaginae /vəjinee/)

1. the muscular tube leading from the vulva to the cervix in women and most female mammals.

(OED)

The human vagina is an elastic muscular tube projecting inside a female. It is usually slightly shorter and thinner than an average male penis, at about 4 inches (100 mm) long and 1 inch (25 mm) in diameter (although there is wide anatomical variation) but its elasticity causes it to be able to accept larger penises and give birth to offspring. It connects the vulva at the outside to the cervix of the uterus on the inside. 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 back (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.

Length, width and shape of the vagina may vary. When a woman gives birth and during sexual intercourse, the vagina temporarily widens and lengthens.[1]

Vaginal lubrication is provided by the Bartholin's glands near the vaginal opening and the cervix and also seeps through the vaginal wall (which does not contain any glands).

The hymen (a membrane situated at the opening of the vagina) partially covers it in many organisms, including many human females, from birth until it is ruptured by sexual intercourse, or by any number of other activities including medical examinations, injury, certain types of exercise, introduction of a foreign object, etc. However, it should be noted that sexual intercourse does not always cause the hymen to be broken, and so (for example) it is not true that a woman with an intact hymen must be a virgin or vice versa.

(wiki)

(Laser Vaginal Rejuvenation Institute of Los Angeles)