Fastag

Human anatomy
The human vagina is an elastic muscular canal that extends from the cervix to the vulva.[1] Although there is wide anatomical variation, the length of the unaroused vagina isapproximately 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).[2] During sexual arousal the vagina expands in both length and width.[3] Itselasticity allows it to stretch during sexual intercourse and during birth to offspring.[4] The vagina connects the superficial vulva to the cervix of the deep uterus.
If the woman stands upright, thevaginal 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 ofthe urethra. The upper one-fourth of the vagina is separated from the rectum by the rectouterine pouch. Above the vagina is the Mons pubis. The vagina, along with the inside of the vulva, is reddishpink in color, as with most healthy internal mucous membranes in mammals. A series of ridges produced by folding of the wall of the outer third of the female vagina is called vaginal rugae. They aretransverse epithelial ridges and their function is to provide the vagina with increased surface area for extension and stretching. Vaginal lubrication is provided by the Bartholin's glands near thevaginal 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's mucus glands secretes differentvariations of mucus, which provides a favorable alkaline environment in the vaginal canal to maximize the chance of survival for sperm.
The hymen is a thin membrane of connective tissue which issituated 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 sexual or non-sexual activity. The tissue may be...