Vagina

Vagina, female reproductive organ consisting of a tubeshaped canal leading from the external genital orifice to the uterus. It measures 4 in (10 cm). The muscular walls, which are covered with a mucous membrane, fall together to give the vagina a slitlike appearance. During sexual intercourse, the male's penis is inserted into the vagina. During birth the vagina serves as the passage through which the baby leaves the mother's body.

See also: Reproduction.