The |vagina| is a canal which extends from the |cervix| to the external genitalia, terminating in the vaginal vestibule. The |urethra| opens into the vaginal wall in a slit-like aperture in the female. The walls of the |vagina| are usually between 3-4 inches (7-10 cm) long, with the ~anterior~ wall being slightly shorter than the ~posterior~ wall. The walls are covered with a |mucous membrane|, and a fold of this membrane, called the |hymen|, may occlude the lower opening of the |vagina|. The fibrous, muscular walls of the |vagina| are capable of dilating and expanding dramatically during |childbirth|.
