Explain mentrual cycle in human females.
Menstrual phase: It lasts for 3-5 days. The menstrual flow results due to the breakdown of the endometrial lining of the uterus and it's blood vessels which forms liquid that comes out through the vagina. Menstruation only occurs if the released ovum is not fertilised.
Follicular phase: It lasts for 8-10 days. During this phase, the primary follicles in the ovary grow to become a fully mature Grafian follicle and simultaneously the endometrium of uterus regerates through proliferation. The secretion of LH and FSH increases gradually.
Ovulatory phase : It lasts for 1 day. There is the release of ovum.
Luteal phase : It lasts for 13 days. There is LH surge. These induce the remaining parts of Grafian follicle to tranform as corpus luteum and it secretes progesterone.
If fertilisation occurs, endomentrium starts preparing for implantation. In the absence of fertilisation, corpus luteum degenerate.
How can the scientific understanding of the mentrual cycle of human females help as a contraceptive measure ?