Explain the Secretary Phase - Menstrual Cycle
After ovulation, the lining of ovarian follicle is stimulated by LH to develop corpus luteum which produces progesterone. The endometrium becomes oedematous, watery mucous increases. This is believed to assist the passage of spermatozoa through the uterus to uterine tubes where the ovum is usually fertilized. The ovum fertilizes by 8 hours. The survival of the sperm is only for 24 hours. The date of ovulation however, cannot be predicted with certainty, even when the cycles are regular. If fertilization of ovum does not occur, cycle goes to a third phase - the menstrual phase.