You can answer many of your own questions and concerns about sex, masturbation, and sexual health by learning more about your own body. Let's jump right in, and take a deeper look at a part of our body we often don't even refer to correctly: the vulva (not the vagina, which is a different part entirely of our female sexual anatomy).
The vulva makes up the parts of our sexual anatomy that we can see by looking (most easily by standing or sitting over a mirror!). This includes the outer and inner labia, the clitoris and clitoral hood, the vaginal and urethral openings.
The outer labia (or labia majora) are folds of skin and fatty tissue that extend downward from the mons (the fatty area of tissue just below the abdomen that is typically covered with pubic hair after puberty) and continue until the perineum (the soft skin between the vaginal opening and the anus which is sometimes colloquially referred to as the 'taint'). The outer labia are also usually covered with hair that extends downward from the mons. The labia majora typically hide and protect the rest of the vulva to varying degrees - they differ considerably in size, color and shape from woman to woman, which is normal. It's also normal for them to be two different sizes. Take a look at Betty Dodson's images of the vulva (the 4 images to the right) to get a sense of how different and unique each woman's labia can be. For many women, stimulation of the outer labia is sexually arousing, and they typically swell and flatten slightly when you're sexually aroused. This is because blood floods the vessels in the genital area and collects there when a woman is turned on.
If you gently pull your outer labia aside, (to reveal the vestibule) you'll see your inner labia (or labia minora). They're folds of skin that go from the bottom of the clitoral hood to just below the vaginal opening. For many women, the inner labia will often stick out through the outer labia and are visible without necessarily having to move the outer labia out of the way. They also range in color from pink to brown or black, depending on skin color, and as a woman matures, they can change in color as well. They can also be wrinkled or smooth, range considerably in size, shape and color and can also be two different sizes. They can also be a source of sexual stimulation or arousal for women and may swell when sexually aroused as well.
The top of the the inner labia creates a little fold of skin - this is the clitoral hood. It covers, protects and connects to the head, or glans, of the clitoris. The clitoris also ranges in size from woman to woman. This part of the clitoris, the part we can see, is only the tip of the iceberg! In its entirety, it extends internally as well (up to about 5 inches!) to create an organ that is just about the same size as the male penis. The sensitivity of the clitoris, both internally and externally, is different for everyone, as well as the ways in which we might like them to be touched or stimulated (if at all). Like the penis, the clitoris becomes swollen and hard when we're turned on. Unlike the penis, however, the sole purpose of the clitoris is for sexual pleasure.
The vaginal and urethral openings are visible when looking at the vestibule as well. The urethral opening can be found by looking below the clit, directly underneath another tiny hood-like shape. Its the tiny hole or opening between the hood-like shape and the vaginal opening. Because the urethral and vaginal openings are very close together, sexual activity can sometimes expose the urethral opening and urinary tract to harmful bacteria which can lead to a host of infections, like a UTI (urinary tract infection). For this reason, it's usually a good idea to urinate after any sexual activity, to decrease the likelihood of harmful bacteria lingering that may have found its way into the urethra during sex. You can also avoid this by using appropriate barrier methods properly, and making sure that all fingers, hands, mouths, toys, or any other organs or objects are clean before they touch or enter you. Just below the urethral opening is the vaginal opening. Even just the external surface of the vaginal opening is a source of pleasure and sexual arousal for many women.
The health of our vulvas, however, can be a relatively complicated matter, particularly when we consider the issues that affect our psychological and emotional well-being, around our perceptions of what we believe vulvas should look like, smell like, feel like, etc., and how our own vulvas compare to some (often, non-existant) ideal. To read about this in more detail, check out Heather Corinna's Give 'Em Some Lip: Labia That Clearly Aint Minor.
There are also physical, medical concerns regarding the vulva. The vulva (and vagina) is relatively sensitive and keeping it healthy and happy depends on a number of conditions. Our bodies produce good bacteria that naturally balance the environment our vulvas need to stay healthy. Anything that disrupts this balance can lead to irritation or infection.
Gannet Health Services at Cornell University created a fact sheet with a range of helpful information about how to avoid infection and maintain optimal vulval and vaginal health. To read more, click here.