|Menstruation And Menstrual Cycles|
The menstrual cycle is the time duration between one menstrual flow to the other. The average time duration is twenty-eight days but it ranges from twenty-one to thirty-five days. The first day of menstrual flow is day one of the cycle
4 Menstrual cycle phases and hormones
4 hormones are involved in the process:-
- Follicular stimulating hormone FSH
- Leutinising hormone LH
- Oestrogen } From the ovary
- Progesterone From the pituitary gland
Follicular stimulating hormones (FSH) and leutinising, hormone (LH) are from the pituitary gland while oestrogen and progesterone are from the ovary.
Menstruation is the regular shedding of the endometrium in a sexually matured non-pregnant woman during menses, the endometrium breaks down and slough off, accompanied by loss of blood, the amount of blood loss is between 30mls and 60mls.
Immediately after menses, the pituitary gland produces FSH. This hormone stimulates the ovary to produce Oestrogen and graffian follicles. The Oestrogen functions to heal and repair the uterine wall following menses. As the Oestrogen level rises, the FSH level decreases. On the 2nd day of its production, that is on the 14th day) LH peaks. This causes ovulation.
The graffian follicle turns to the corpus luteum. The corpus luteum produces progesterone. With the production of progesterone, the levels of FSH, LH, and estrogen fall back to normal This progesterone causes the proliferation of the uterine wall. The wall becomes thickened, folded, and invaded by numerous blood vessels. However, as the corpus luteum develops fully the corpus luteum regresses and its two hormones fall.
2nd the week, there is no fertilization and implantation, the estrogen level rises and peak again. If by the end of the there is, therefore, no hormonal support for the endometrium. The endometrium is shed as menstrual flow.