Ovarian cycle

The ovarian cycle is a series of changes that happen in the ovary starting at puberty and continue until menopause. A typical ovarian cycle takes 28 days, but varies from person to person. The ovarian cycle has 3 phases:

1. Follicular phase: During the follicular phase, some primordial follicles will be stimulated to grow and continue with meiosis. The primordial follicle grows into a primary follicle, then a secondary follicle, and tertiary follicle until it is a mature follicle that is ready to release the oocyte from the ovary.
2. Ovulation. The mature follicle ruptures and releases the oocyte into the uterine tube.
3. Secretory phase. The follicular tissue left behind in the ovary heals, and grows larger. It becomes known as the corpus luteum. Eventually, the corpus luteum degenerates into the corpus albicans.

Figure 1: Illustration of the ovarian cycle that takes place inside the ovary. The illustration shows the different phases of the ovarian cycle including the follicular phase, ovulation, and the secretory phase. Although this image depicts the changes that occur as a follicle matures, keep in mind that a follicle does not move around the ovary. Wherever the primordial follicle is located, it will mature in that spot.