The ovaries are paired female gonads, the main female endocrine organs where oocyte maturation and sex hormone synthesis occur.

They are located on either side of the uterus in the ovarian fossa found on the lateral wall of the true pelvis at the level of the sacroiliac joint under the bifurcation of the common iliac artery (under the external and in front of the internal iliac artery and ureter).

Ovaries are intraperitoneal organs, and they are mobile. Superiorly is located the infundibulum of the Fallopian tube. They lie laterally to the uterus on both sides and are connected to it with the help of the proper ovarian ligament (also called the uteroovarian ligament), as well as with the broad ligament and with its mesovarium.

The proper ovarian ligament connects the inferior pole of the ovary with the uterus below the uterine horn, which is the connection site of the body of the uterus and Fallopian tube. The proper ovarian ligament lies within the broad ligament.

The mesovarium is a double layer of the peritoneum, and it is a subdivision and a part of the broad ligament. It goes from the posterior surface of the broad ligament to the anterior margin and surface of the ovary.

Both mentioned ligaments fix the ovary in its place, but there is another ligament. It is the suspensory ligament of the ovary that extends between the wall of the pelvis and the superior pole of the ovary. The ligament contains the ovarian artery and vein, and ovarian plexus.

Ovaries have the size and shape of a bean or almonds. The normal ovary is 2,5-5 cm in length, 1,5-3 cm in width and 0,8-1,5 cm in thickness (average size is 3,5 x 2,5 x 1,5 cm). They weigh 4-8 grams.

The volume of the ovary changes during the lifetime. Young girls have smaller ovaries compared to an adult women. Women who have given birth tend to have larger ovaries than those who have not. The volume and size decrease with age.

Each ovary has two poles, two margins, and two surfaces.

The poles or extremities are:

Superior pole (also called the tubal pole) - superior to it is located the infundibulum of the Fallopian tube; therefore it is covered by the fimbriae of the infundibulum;
Inferior pole (uterine pole) - is pointed downward; it is thinner and located closer to the uterus.

The margins of the ovaries are:

Anterior margin (sometimes also referred to mesovarian margin) - attached to the posterior surface of the mesovarium; in the middle of the margin is located the hilum of ovary through which in the ovary enter the blood and lymph vessels and nerves;
Posterior margin (also called the free margin) - it is rounded and convex.

The surfaces are as follows:

Lateral
Medial

The external surface of the ovary is covered by the tunica albuginea, and underneath it each ovary consists of two parts:

Cortex - outermost and the largest part; parenchyma where ovarian follicles in various stages of differentiation are located in between the connective tissue;
Medulla - innermost part, located in the center; contains connective tissue, blood and lymph vessels, nerves of the ovaries.

There are two primary functions of the ovaries, and they are:

Oogenesis - differentiation, and release of oocytes; therefore, ovaries provide the reproductive function;
Production and secretion of sex hormones (progesterone, estrogen, also a small number of androgens, for example, testosterone).

NOTE: a newborn female has around 1 000 000-2 000 000 follicles. When puberty is reached at about 11-15 years old, there are only 300-500 000 follicles, and they begin to maturate. Approximately 300-500 follicles mature during a lifetime. Each menstrual cycle is approximately 28 days long, and in each cycle mature and ovulate one, rarely two follicles. The ovaries function until about 45-50 years of age.

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Ovaries