ABSTRACT
The ovaries lie in the pelvis each side of the uterus at the ends of the fallopian tubes. Each ovary is about the size and shape of an almond. It is attached to the pelvic wall and to the uterus by ligaments. The ovary has an outer cortex and an inner medulla. In the cortex are the granulosa and theca cells that are responsible for producing the ovarian hormones. The relationship between the estrogen produced by the ovaries and the testosterone produced by the testes is a very close one molecularly. They differ by only one molecule, and testosterone is the precursor to estrogen. Within the ovaries, testosterone is converted to estrogen by aromatase. The ovaries produce two main classes of hormone: estrogens and progestins. In humans, the estrogen is estradiol, and the progestin is progesterone. The ruptured ovarian follicle left behind after ovulation becomes a corpus luteum. This now produces progesterone as well as estradiol.
