Ovary illustration

Anatomy & Physiology

The ovaries are a woman's reproductive organs. There are two ovaries, both located within the pelvis (lower region of the abdomen, between the hip bones), one on each side of the womb (uterus). The ovaries have a size and shape comparable to a large olive.

The role of the ovaries is to produce eggs and also the female hormones. The primary female hormones released by the ovaries are estrogen and progesterone. These hormones regulate the menstrual cycle, pregnancy and development of a woman's physical appearance including breasts, shape and hair.

Ovarian Function

During the first half of a woman's menstrual cycle—about 2 weeks before ovulation, an egg is released. The hypothalamus in the brain sends a hormonal signal to the pituitary gland to release follicle-stimulating hormone (FSH) into the bloodstream. When the blood-borne FSH reaches the ovaries, it spurs the Graafian follicles to grow and produce estrogen. Additional estrogen is made by hormone-producing tissue within the stroma. One Graafian follicle in an ovary begins to outgrow the other follicles while the estrogen level is increasing.

Meanwhile, once the estrogen level has peaked, the pituitary gland stops the output of FSH and begins to release luteinizing hormone (LH). The LH causes the Graafian follicle to bubble out on the outside of the ovary, burst, and eject its egg into the fallopian tube. This process of ovulation occurs on or about the 14th day of the menstrual cycle. The ovulated egg travels through the fallopian tube for 5 to 7 days, after which it is released into the uterus.

Connective Tissue & the Ovaries

The ovaries are held in place by bands of fibrous tissue known as ligaments. The ligament of the ovary is a rounded cord that extends from the upper uterus to the lower, inner region of the ovary. The fimbria ovarica are fringe-like tissues that attach the ovaries to the fallopian tubes. The round ligaments are two cords, 4 to 5 inches in length, that connect with layers of the broad ligament (ligament that attaches to each side of the pelvic wall to support the uterus) in front of and below the fallopian tubes.

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Blood Vessels, Nerves & the Ovaries

The ovarian arteries, which are offshoots of the abdominal aorta, furnish the ovaries and fallopian tubes with blood. They enter the ovary via an attached border, or hilus. The ovarian veins parallel the route of the arteries, forming a tangled network in the broad ligament known as the pampiniform plexus.

The nerves that supply the ovaries are branches of the inferior hypogastric nerve, the pelvic plexus (network), the ovarian plexus, and uterine nerves within the fallopian tubes.