Chapter 7: Reproductive cyclicity (estrous and menstrual cycles) provides females with repeated opportunities to become pregnant.  The two types of reproductive cycles are the estrous cycle and the menstrual cycle.
An estrous cycle consists of the physiologic events that occur between successive periods of sexual receptivity (estrus or heat) and/or ovulations.  Each cycle consists of a follicular phase and a luteal phase.  The follicular phase is dominated by the hormone estradiol from ovarian follicles.  Estradiol causes marked changes in the female tract and initiates sexual receptivity in females with estrous cycles.  The luteal phase is dominated by the hormone progesterone from the corpus luteum that prepares the reproductive tract for pregnancy.  Periods of time when estrous cycles cease are called anestrus.  Anestrus is caused by pregnancy, season of the year, lactation, certain forms of stress and pathology.  Amenorrhea refers to the lack of menstrual periods and is caused by many of the same factors that cause anestrus.

Chapter 8: The follicular phase consists of four major events.  They are:  1) elevated gonadotropin release from the anterior lobe of the pituitary; 2) follicular growth and preparation for ovulation; 3) sexual receptivity and 4) ovulation.  Estrogen is the dominant hormone that is produced by developing follicles and causes profound changes in the reproductive tract preparing it for copulation.  Reproductive behavior is induced  by estrogen in non-primate mammals.  Estrogen also controls the onset of the preovulatory LH surge that causes ovulation. Ovulation is a cascade of physiological and biochemical changes that culminate in rupture of dominant follicles and release of the oocyte from the ovary.

Chapter 9: The luteal phase consists of three major processes.  They are: 1) the transformation of follicle cells into luteal cells after ovulation (luteinization); 2) growth and development of the corpus luteum so that it produces high quantities of progesterone (diestrus); 3) destruction of the corpus luteum (luteolysis) resulting in a subsequent follicular phase.  Lysis of corpora lutea is brought about by prostaglandin F2α  that is produced by the uterine endometrium in most mammals and by the ovary in humans.  Lysis of corpora lutea is followed by a marked reduction in progesterone.  The negative feedback exerted by progesterone on the hypothalamus is removed and the female enters a new follicular phase because the pulse frequency and amplitude of GnRH increases thus causing FSH and LH to increase.  In humans, luteolysis causes the initiation of menstruation that is followed by another follicular phase.