1. The Menstrual Cycle Purpose: to bring an egg to maturity and to prepare the reproductive system for pregnancy. 28 day cycle (on average) Repeats continuously until menopause

2. Four Phases 1. Flow phase (5 days) – shedding of the endometrium (if no fertilization occurs)

3. Four Phases 2. Follicular Phase (days 6-13) – development of follicle within one of the ovaries Follicles contain developing oocye (egg) and as they develop begin to secrete estrogen

4. Four Phases 3. Ovulation (day 14) – egg bursts from the ovary and the follicle cells develop into the corpus luteum

5. Four Phases 4. Luteal Phase (days 15-28) - development of the corpus luteum Corpus luteum secretes both progesterone and estrogen. - Prepares uterus for an embryo

6. The Full Cycle