The Female Body The vagina is a thin walled-tube, 8 to 10 cm long. It lies between the bladder & the rectum & extends from the cervix to the body exterior. The urethra is embedded in its anterior wall. Often called the birth canal, the vagina provides a passageway for delivery of an infant & for menstrual flow. Since it receives the penis (& semen) during sexual intercourse, it is the female organ of copulation. The highly distensible wall of the vagina wall consists of three coats: An outer fibroelastic adventitia. A smooth muscularis. A mucosa marked by transverse ridges or rugae, which stimu