The vulva is the external genital organs of the female mammal. This article deals with the vulva of the human being, although the structures are similar for other mammals. The vulva has many major and minor anatomical structures, including the labia majora, mons pubis, labia minora, clitoris, bulb of vestibule, vulval vestibule, greater and lesser vestibular glands, and the opening of the vagina. Its development occurs during several phases, chiefly during the fetal and pubertal periods of time. As the outer portal of the human uterus or womb, it protects its opening by a "double door": the labia majora (large lips) and the labia minora (small lips). The vagina is a self-cleaning organ, sustaining healthy microbial flora that flow from the inside out; the vulva needs only simple washing to assure good vulvovaginal health, without recourse to any internal cleansing. The vulva has a sexual function; these external organs are richly innervated and provide pleasure when properly stimulated. In various branches of art, the vulva has been depicted as the organ that has the power both to "give life" (often associated with the womb), and to give sexual pleasure to humankind. The vulva also contains the opening of the female urethra, and thus serves the vital function of passing urine.