And finally, this describes the development of that follicle, the rupture of the follicle, the release of the secondary oxide and the formation of the corpus luteum and the eventual deterioration of the corpus luteum into the corpus albicans assuming no fertilization actually took place. So in this lecture we're going to assume that no fertilization actually takes place. So let's begin at the beginning what happens during the follicular phase. So during the follicular phase, at the beginning we have menstruation. And so part of the endometrium is actually discharged along with that secondary oicide. And so what begins to happen is the hypothalamus of that woman begins to release the gonadotropin releasing hormone GnRH.