In mammalsthe vagina is the elastic, opening part of the female genital tract. In humans, it extends from the vulva to the cervix. The outer vaginal opening is normally partly covered by a membrane called the hymen.
At the deep opening, the cervix vagina of the uterus bulges into the vagina. The vagina allows for sexual intercourse and birth. It also channels menstrual flow menseswhich occurs in humans and closely related primates as part of the monthly menstrual cycle. Although research on the vagina is especially lacking for different animals, its vagina, structure and size is documented as varying among species.
Female mammals vagina have two external openings in the vulva, the urethral opening for the urinary tract and the opening opening the genital tract.
This is different from male mammals, who usually have a single urethral opening vagina both urination and reproduction.
Female Sexual Anatomy | Vulva, Vagina and Breasts
The vaginal opening is much larger than the nearby urethral opening, and both are protected vagina the labia in humans. In amphibiansbirdsreptiles opening monotremesthe opening is the single external opening for the gastrointestinal tract, the urinary, and reproductive tracts.
vagina To accommodate smoother penetration of opening vagina during sexual intercourse or other sexual activityvaginal moisture increases during sexual arousal in human females and other female mammals. This increase in moisture provides vaginal lubricationwhich reduces friction. The texture of the vaginal walls creates friction for the penis during sexual intercourse and opening it toward ejaculationenabling fertilization.