The vulva is the external genital organs of the human female. It includes the mons pubis, the clitoris, the labia majora and minora, the vulval vestibule, the vestibular bulbs and glands, the opening of the urethra, the hymen, and the vaginal orifice. It does not include the internal female sexual organs of the vagina, uterus, ovaries, and Fallopian tubes.
The topmost structure of the vulva is the mons pubis, a small mound of fatty tissue covering the pubic bone. In adult women, it is typically covered with pubic hair. The openings of the urethra and the vagina, or birth canal, are contained in the vulval vestibule, which is covered and protected by two sets of fleshy lips, the thin interior labia minora, and the thick exterior labia majora. The opening of the urethra is superior to that of the vagina. The urethra is the tube through which urine exits the body from the bladder, and the vagina is the structure used for sexual intercourse, menstruation, and childbirth.
The clitoris is located at the front of the vulva, where the labia minora meet. The visible portion of the clitoris is called the clitoral gland, and it is covered by the clitoral hood, which is analogous to the foreskin in males. The clitoris contains many nerve endings and is therefore very sensitive. It becomes erect when sexually stimulated.
The opening of the vagina is sometimes covered with a thin membrane called the hymen, which has traditionally taken to be a sign of virginity. However, there are many ways in which a girl's or woman's hymen can be broken while she is still a virgin, and the size and thickness of the hymen greatly varies among individuals, so the presence or absence of a hymen does not reliably indicate whether one is a virgin. In some women, the hymen is so thick that it must be surgically removed in order to allow for normal menstruation or sexual intercourse.
The vulva is supplied with a few different sets of glands, organs that secrete fluids. The labia majora contain sebaceous glands, which secrete an oily, lubricating substance called sebum. Sebaceous glands are also found all over the skin, except for on the palms of the hands and the soles of the feet. The two sets of glands unique to the vulva are Bartholin's glands, or the greater vestibular glands, and Skene's glands, or the lesser vestibular glands.
Bartholin's glands are located just below the vaginal opening on either side, one on the right and one on the left. They secrete mucous, usually when a woman is aroused, in order to lubricate the vaginal opening to ease sexual intercourse. Skene's glands are located just above the vagina on either side, close to the urethral opening. Skene's glands are not fully understood, but are theorized to be the cause of the controversial female ejaculation, in which fluid is expelled from either the urethra, Skene's glands, or both during a woman's orgasm.