genitalia. Two folds of skin, the labia major and labia minor, form the boundaries to the vulva. Within these boundaries are located the opening to the vagina to the rear, then the opening to the urethra at the mid-point, and the clitoris at the front. Formed by the same embryonic tissue that gives rise to the male penis, the clitoris also becomes engorged with blood during sexual arousal and serves as a major source of stimulation during copulation.
