Histology Fact Sheet: Ovaries

The term for the production of gametes is called gametogenesis. Gametogenesis in the female is referred to as oogenesis. The ovary is the organ where gametogenesis (oogenesis) occurs. Ovulation is the release of an oocyte and occurs every 28-30 days. The developing gametes are called oocytes. The
mature gamete is an ova.

Histology of the Ovary

The ovary is covered with germinal epithelium. Underneath the germinal epithelium is connective tissue called the tunica albuginea. The outer region of the ovary is called the cortex. The inner region of the ovary is called the medulla. Histology hint from Sarah Bellham: The outer region of some other organs is also sometimes called a cortex. The inner/middle region of some other organs is also sometimes called a medulla. The ovarian follicle contains the oocyte.

Primordial Follicle

A primordial follicle is a primary oocyte in the outer region of the cortex. It is arrested in the first meiotic prophase. It is surrounded by flattened follicular epithelial cells.

Primary Follicle

The primary follicle is marked by the surrounding of flattened (squamous) follicular cells becoming cuboidal and the oocyte becomes bigger.

Secondary Follicle

The presence of the antrum is a characteristic of a secondary follicle. A follicle at this stage is also called an "antral follicle".

Graffian Follicle

The mature follicle is also called the Graffian follicle. The follicle which is ovulated is the Graffian follicle. The connective tissue layer around the primary follicle is the theca folliculi. The follicular cells are granulosa cells. The acidophilic glycoprotein coat surrounding the oocyte is the zona pellucida. A cavity within the
follicle is the antrum.

Corpus Luteum

"Yellow body".  The corpus luteum forms from a Graaffian follicle after the release of the oocyte.

Corpus Albicans

"White body". Remnant from corpus luteum.

Histology slide of an ovary
Histology slide courtesy of Education Interactive Human Histology Photo CD.

Sources:

Histology: A Text and Atlas
Michael H. Ross/Edward J. Reith