"Boys have a penis, girls have a vagina." This is often how parents describe sexual differences to their children. As a result, many of us grow up thinking that everything below a woman's waistline is her vagina, when in fact it's but one small part of the system. Though the vagina is the focus of this article, it's impossible to describe it without spending a few minutes describing everything surrounding it.
Many people say "vagina" when they're referring to a woman's external genitalia, but this area is actually the vulva. The vulva encompasses the outer and inner labia, the clitoris, the clitoral hood, the opening to the urethra and the vaginal opening.
At puberty, pubic hair starts growing on the mons, or the tissue that covers the pubic bone, as well as on the labia majora, or the outer lips. The labia majora unfold to reveal the labia minora, or inner lips; these lips are much thinner than the protective outer lips. The color and size of both sets of lips vary from woman to woman. Under the point where the inner lips meet are the clitoral hood and the clitoris. The clitoris, which is covered with more nerve endings than the penis, plays an important role in female sexual pleasure, which we'll discuss later. But researchers are learning more all the time about clitoral anatomy. The head of the clitoris, which might be the size of a pea or even a child's finger, can be seen, but it turns out that the clitoris also extends inside the body. The clitoris has a shaft that divides into two legs of tissue that extend 5 inches (12.7 cm) on each side of a woman's body. All told, the clitoris is just about the same size as the male penis.
Let's consider the head of the clitoris the engine of a nether-region train; the anus would be the caboose. The two middle cars are the urethral and vaginal openings. The urethra is the next car down from the clitoris, and while men use their penises for both urination and ejaculation, the systems are separate in women. Urine doesn't come out of the vagina; instead, the urethra connects to the bladder.
Next to the urethral opening is our star attraction for this article: the vaginal opening, which leads to the vagina.