http://www.girlshealth.gov/

Body

Home Body Reproductive health How the reproductive system works

How the reproductive system works

Your reproductive system: on the inside

The ovaries are two small glands next to the uterus. The uterus (or womb) is like an inside pocket where a baby grows. Ovaries begin to make more estrogen and other hormones during puberty. This sparks the start of your menstrual cycle, which includes your period and other hormonal changes.

The ovaries release or let go of one egg (ovum) about once a month, from the one million or so eggs it has been storing since before you were born. This is called ovulation. The egg moves along a fallopian tube, which connects the ovary to the uterus. It takes around 3 or 4 days for the egg to get to the uterus. During this time, the lining of the uterus (called the endometrium) becomes thicker with blood and fluid to make itself a better home for a baby. You will get pregnant if you have sex with a male, and his sperm fertilizes or joins the egg on its way to your uterus. Barrier birth control methods such as condoms can prevent sperm from passing during sexual intercourse, but these do not work 100 percent of the time. If a fertilized egg attaches itself to the lining of the uterus, a baby may start to grow. If the egg doesn’t become fertilized, it will be shed along with the lining of your uterus during your next period. The egg is too small to see.

The vagina, which is made of muscle, is a hollow canal or tube that can grow wider to deliver a baby that has finished growing inside the uterus. The opening of the vagina is covered by the hymen, which is a thin piece of tissue that has one or more holes in it. Sometimes a hymen is stretched or torn when you use a tampon or after a first sexual experience, but this does not always happen; sometimes the hymen stays the same. If it does tear, it may bleed a little bit.

The cervix is the narrow entryway in between the vagina and uterus. The opening of the cervix is very small, so a tampon will not slip through here and get lost. At the same time, the muscles of the cervix are flexible so that it can expand to let a baby pass through when she or he is being born.

Your reproductive system: on the outside

Outside of the body, the entrance to the vagina is covered by the vulva. The vulva has five parts: mons pubis, labia, clitoris, urinary opening, and vaginal opening.

The mons pubis is the mound of tissue and skin just below your stomach. This area becomes covered with hair when you go through puberty. The labia are the two sets of skin folds (often called lips) on either side of the opening of the vagina. The labia majora are the outer lips and the labia minora are the inner lips. The labia minora cover a small sensitive bump called the clitoris, which is at the bottom of the mons pubis. Below the clitoris is the urinary opening, which is where your urine leaves the body. Below the urinary opening is the vaginal opening, which is the entry into the vagina.

Learn more about the female reproductive system and getting your period.

Content last updated June 18, 2008

top