Ovaires

The ovaries are paired almond-sized glands measuring 2-3 centimeters in length, located within the pelvic region. They are anchored by the mesovarium, a peritoneal extension connecting them to the broad ligament. The suspensory ligament houses blood and lymphatic vessels, while the ovarian ligament tethers the ovaries to the uterus. Blood vessels and nerves enter and exit through the hilum.

The ovary consists of several distinct layers. The outermost ovarian mesothelium is simple cuboidal or squamous epithelium. Beneath it lies the tunica albuginea, composed of dense, irregular connective tissue. The ovarian cortex contains follicles and stromal cells, while the ovarian medulla contains blood vessels, lymphatic vessels, and nerves.

Ovarian follicles are supportive complexes within the ovarian cortex that house oocytes at different growth stages. Each oocyte is nestled within a follicle surrounded by stromal cells and collagen fibers. A mature Graafian follicle is a large, fluid-filled structure that ruptures during ovulation to release the secondary oocyte for potential fertilization.

After ovulation, the remnants of the ruptured follicle transform into the corpus luteum, which produces progesterone, estrogens, relaxin, and inhibin. These hormones support early pregnancy and regulate the menstrual cycle. Eventually, the corpus luteum deteriorates into fibrous scar tissue called the corpus albicans.

The ovarian stroma is an intricate lattice of tissue that constitutes most of the ovarian interior within the cortex. It provides structural support and surrounds the developing follicles and oocytes. The stroma contains stromal cells and collagen fibers that create the supportive environment necessary for oocyte maturation and follicle development.

The ovarian cortex is the outer layer housing follicles, oocytes, and stroma where follicle formation and maturation occur. The ovarian medulla lies beneath with a loosely defined border and contains an extensive network of blood vessels, lymphatic vessels, and nerve fibers that supply the ovary.

The tunica albuginea is a layer of dense, irregular connective tissue located directly beneath the ovarian mesothelium on the ovarian surface. It forms a protective barrier and provides structural support to the underlying ovarian cortex containing the follicles and oocytes.