The image shows a schematic illustration of the ovary. The round ovary (left) is encompassed by the fimbrial funnel (infundibulum tubae uterinae) that leads into the uterine tube and thus into the uterus. The picture specifically shows the maturation of the ovarian vesicular follicles (Graafian follicle), as well as the corpus luteum and corpus albicans. The ovarian follicles consist of egg cell and follicle cells. According to their state of development, one distinguishes between primordial, primary, secondary, tertiary, and Graafian follicle. During the ejection of the egg cell (ovulation), estrogen (a steroid hormone) is released (blue). Later on, the corpus luteum will additionally produce progesteron.