The ovaries are two glands in the female body that produce reproductive cells (eggs) and hormones.

In pre-menopausal women, the ovaries periodically release eggs which travel into the uterus or womb. In preparation, the uterus builds up a thick wall lined with blood-rich tissue. Pregnancy occurs if the egg is fertilized by sperm from a male and lodges in the uterus as an embryo. If the egg is not fertilized, both it and the uterine tissue are discharged (menstruation).

The ovaries also produce at least two known hormones, estrogen and progesterone. These hormones are responsible preparing the uterus for pregnancy, and for the development and maintenance of female characteristics such as growth of breasts.