The structure and function of the female reproductive system is viewed in diagrams, and outlined. Full discussion of the menstrual cycle from day 1 to day 28, depicting the levels of hormones, the conversion of the follicles, the increase in cell, tissue, and blood vessels as the functional layer of the endometrium changes over the cycle. Formation of the placenta if fertilization has occurred, or sloughing off and removal of the built up endometrium if fertilization has not occured.