Ovulation

A hormone from the anterior pituitary will cause the mature follicle to rupture around day 14 of a 28 day ovarian cycle. This event is known as ovulation. During ovulation, the ovary releases:

1. Secondary oocyte and polar body surrounded by the

2. Zona pellucida and

3. Multiple layers of granulosa cells. The granulosa cells that are ovulated with the secondary oocyte are known as the corona radiata.

The secondary oocyte enters the uterine tube and can become fertilized for the next 12-24 hours. If fertilization does not occur, then the secondary oocyte along with the corona radiata will die and degenerate.

Figure 1: Illustration showing a secondary oocyte leaving the ruptured mature follicle inside the ovary.