ovaries

ovaries: The two ovaries (OH-vuh-reez) are the main glands that produce sex hormones in women, corresponding to the testes in men; the general name that covers both sets of glands is gonads (GOH-nads). The ovaries are the repository of hundreds of thousands of precursors to egg cells, called ova (OH-vuh; the singular is ovum). Each month (28 days, usually), from the time a girl reaches puberty (around the age of 12 to 15), one of the ovaries produces and releases a single ovum. After this has happened some 400 or so times, the woman's ovaries shut down. This time in a woman's life is known as menopause.

Size and location Each ovary is about the size of a hen's egg or somewhat smaller. The ovaries are located symmetrically in the pelvis at either side of and somewhat above the uterus, which is itself at the end of the birth canal and just above the bladder. Each ovary is at one end of a Fallopian tube, which has the uterus at its other end - although the tube passes around the ovary, embracing it to some degree.

Role About once every four weeks in a woman of reproductive age the pituitary gland, located just below the brain, releases a hormone called follicle-stimulating hormone (FSH) into the blood. When FSH reaches the ovary, it stimulates several of the primitive Graafian follicles to begin the development, called ripening, of their contents, which are the precursors of ova. Each precursor egg is in its own follicle. After about ten days one ovum ripens and the others fade away. When the ovum is ripe, it breaks out of the follicle. The follicle soon fills with a special yellow material called the corpus luteum (KAWR-puhs loo-TEE-uhm, which is Latin for "yellowish body"). The corpus luteum makes a hormone that signals the uterus that an egg is on the way. From time to time, more than one egg ripens during the same month, creating the possibility of fraternal twins or other multiple births. Identical twins result from a different mechanisma fertilized egg splits into two parts that continue development as separate embryos.

Conditions that affect ovaries The ovaries, like the testes, are subject to cysts (fluid-filled sacs), which are common, and cancer, which is rare. Ovarian cancer is not easy to detect in early stages, when a cure can be easily effected by removal of the cancerous ovary and nearby reproductive organs and lymph nodes.
Undetected ovarian cancer may signal itself with pain and considerable swelling of the lower abdomen. See a physician if these symptoms develop.
Pelvic inflammatory disease is any infection of the uterus, where such infections usually begin, Fallopian tube, and ovaries. It is fairly common, especially among the young and sexually active. Since it can damage the ovary or Fallopian tube, PID also requires treatment as soon as symptoms develop.