Reproductive System

Without the reproductive system, the history of the human race would be Adam, Eve, The End. But thanks to the fallopian tubes, ovaries, uterus, cervix and vagina, history has been made and the human race continues. Each month in almost every woman of childbearing age, an ovary releases an egg, which moves through a fallopian tube to the uterus. If the egg is fertilized, it burrows into the lining of the uterus, grows into a fetus and comes out the cervix and vagina a full-fledged human being.

Painful, useful and pleasurable, the uterus gives us cramps, childbirth and orgasms. It can transfigure itself from a muscle-walled one-inch cavity to a womb big enough to hold a six- to ten-pound baby. But its removal is the second most performed surgery in the United States. (See "Hysterectomy--And Other Options" on page 424.)

* Half of all women of childbearing age get menstrual cramps, caused by contractions of the uterus--that incredible expansive organ of muscular tissue. (To learn how to relieve monthly cramps, see "Menstrual Symptoms" on page 242.)

* Yeast infections are a common form of an inflammation of the vagina called vaginitis. They itch like mad and produce redness, odor and a discharge. (For tips on how to control yeast, see "From Yeast to Rest" on page 428.)

* The endometrium is the lining of the uterus. But sometimes endometrial tissue grows where it shouldn''''t--on the fallopian tubes or the ovaries, for instance--and blocks conception. It''''s a common cause of infertility. There are other causes, too. (For ways to help safeguard your fertility, see "Fertility" on page 141.)

* The cervix is the lowest part of your uterus. Normally, it''''s as thin as a small straw, but during childbirth it expands to the width of three fingers for the baby''''s passage. That happens during labor, and it is laborious. (For some labor-saving tips to ease discomfort, see "Delivering the Goods" on page 73.)

* Cancer of the lining of the uterus (endometrial cancer) and ovarian cancer are two diseases women worry about. Though women have worried about some risks associated with birth control pills, research has shown that the Pill reduces the risk of both gynecological cancers. (To find out where the birth control pill stands today, see "Myth #3: The Pill Isn''''t Safe" on page 22.)

* Somewhere in our forties, the ovaries start to decrease their production of estrogen, the hormone that''''s an ingredient in so many biological stews. Menstruation becomes irregular, and we may begin getting hot flashes or night sweats. Perimenopause is the time before menopause, which is technically your last period. It can last anywhere from two to ten years. (To plan for the big pause and the long perimenopause that precedes it, see "Planning Ahead" on page 229.)