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. And what GnRH does is it stimulates the release of the follicle stimulating hormone and the luteinizing hormone from the interior pituitary gland. Now these two hormones then go down to the ovary and affect the immature follicle the follicle stimulating hormone as well as LH causes that follicle to begin to develop into the secondary follicle. So what happens first is the primary follicle or the primary oocide in the primary follicle undergoes meiosis one and produces a secondary follicle.