Internal anatomy is the name for organs, etc., that you can't see because they're inside your body. Most of your female private parts are internal, below your belly, but closer to your backbone than your belly button. Look at the illustration as you read about the organs (female private parts) and you'll get a better picture of what's going on. 

1. Vagina (Vuh-JEYE-nuh)

The vagina, also called the birth canal, is inside of the body. It is the entrance to the reproductive system.

A lot happens in the vagina. You can see the opening of it below your urethra (the place you urinate from), but what you can't see is that the vagina goes up and into your body. It is a narrow "tunnel" about three to five inches long. The walls of the vagina are usually touching. It's a little like a balloon that hasn't been blown up (this is called a "potential space" an area that seems closed, but that can open up into a larger space). The vagina usually opens easily for a tampon or sexual intercourse.

During pregnancy, the vagina changes to accommodate a baby passing through. The vagina is where sperm from a man's penis is released into a woman's body during sexual intercourse. It's also where your menstrual flow leaves your body. (Note how the vagina slants from the small of your back toward your waist. This fact is important for inserting a tampon.)

2. Cervix (SER-Vicks)

The cervix is the lower part of the uterus, sometimes called the neck of the uterus. It's located at the top of the vagina. The cervix is about as wide as a quarter, but the opening in the center is only as large as a pencil point. There's mucus in the cervix that protects the rest of the reproductive anatomy from bacteria. Menstrual flow passes through the opening, then into the vagina, and then outside the body.

3. Uterus (YOU-ter-us)

The uterus is also commonly called "the womb." It is a pear-shaped organ about the size of your fist, that can grow and stretch large enough for complete development of an embryo and fetus. There are three openings to the uterus. At the bottom, the cervix opens into the vagina. At the top, two tubes are attached on either side—these are called fallopian tubes.

4. Endometrium (en-doe-ME-tree-um)

The inner lining of the uterus is called the endometrium. This is the part of the uterus that gets full with blood each month, and is released from your body during your period if you're not pregnant.

5. Fallopian (fah-LOW-pee-un) tubes

These soft tubes go from the uterus to the ovaries (see below). The fallopian tubes are where eggs get fertilized; "fertilization" is the word for when an egg comes in contact with sperm and can therefore, develop into an embryo, then a fetus, and later, a baby. The fallopian tubes are the passageway where a fertilized egg travels to the uterus.

6. Ovaries (OH-ver-eez)

The fallopian tubes lead to the ovaries, which are oval-shaped places that hold eggs, or ova. Measuring about an inch and a half wide and an inch long, the two ovaries are located on either side of the uterus.

The ovaries hold all of a woman's eggs. Girls are born with all the eggs they'll ever have—about 250,000 in each ovary. Once a girl goes through puberty, her body releases a mature egg each month.