vagina

The vagina (from Latin, literally "sheath" or "scabbard") is actually a fibromuscular tubular that tract leading from the uterus to the exterior of the body in the female placental mammals and other marsupials, or to the cloaca in the female birds, monotremes, and for some reptiles. Female insects and other invertebrates also have a vagina, which is the basic terminal part of the oviduct. The Latinate plural (rarely used in English) is term vaginae.
In a common speech, the term "vagina" is frequently used to refer to the vulva or female genitals generally; strictly speaking, the vagina is just a specific internal structure and the vulva is the exterior genitalia only.

Human anatomy

Close up of a vagina

The human vagina is an elastic muscular canal that essentially extends from the cervix to the vulva. Although there is a wide anatomical variation, the length of the unaroused vagina is almost approximately from 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). During the sexual arousal the vagina that expands in both length and width. Its elasticity that actually allows it to stretch during sexual intercourse and during birth to offspring. The vagina connects the superficial vulva to the exact cervix of the sometime deep uterus.

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

Physiological functions of the vagina

The vagina has a numerous biological functions.
Uterine secretions

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

The concentration of the nerve endings that lie then close to the entrance of a woman's vagina can provide pleasurable sensation during sexual activity, when get stimulated in a way that the particular woman enjoys. During the sexual arousal and particularly stimulation of the clitoris, the walls of the vagina thus self-lubricate, reducing the friction during sexual activity. Research has found that its portions of the clitoris extend into the vulva and vagina.

G-spot

An erogenous zone that referred to commonly as the G-spot is that 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 done appropriately during sexual activity. A G-Spot orgasm may be in fact responsible for female ejaculation, leading some doctors and researchers to believe that G-spot pleasure comes from the top Skene's glands, a female homologue of the prostate, rather than to any particular spot on the vaginal wall. Some researchers those deny the existence of the G-spot.

Childbirth

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