So we go from a primary OSI to a secondary OSI. Now, once that follicle has matured, the follicle ruptures in a process known as ovulation. The second phase and ovulation releases that secondary OCIL into the peritoneal cavity and then into the fallopian tube. And the final phase is called the luteal phase. This is the process by which inside the ovary we form that corpus luteum that acts as a gland during the menstrual cycle, as we'll see in just a moment. Now, menstruation actually takes place at the beginning of the follicular phase and at the end of our luteal phase.