Ovaries

At very low magnification, the ovary appears as a roughly oval structure. It has two main regions: the cortex and the medulla. The cortex forms the outer portion of the ovary. It contains numerous ovarian folliclesStructures in the ovaries that contain developing oocytes. at various stages of developmentThe process of growth and differentiation.. These follicles are embedded within a dense connective tissue stroma. These follicles—ranging from primordial to mature (Graafian) follicles—are visible as circular or oval profiles scattered throughout the cortex. The surface of the ovary is covered by a single layer of germinal epithelium. This is a simple cuboidal or squamous epithelium. Beneath this layer lies the tunica albugineaA fibrous layer surrounding the ovary., a dense connective tissue layer. This gives the ovary a smooth outer appearance.

The medulla, found in the central region of the ovary, appears less cellular and more vascular than the cortex. It consists mostly of loose connective tissue, containing blood vessels, lymphatics, and nerves. At low magnification, the boundary between the cortex and medulla may appear somewhat indistinct. The medulla is recognizable by its relative lack of follicles. It also has prominent vascular structures.