Hormonal Control Of The Menstrul Cycle

The menstrual cycle takes approximately 28 days, with the first day of menstruation regarded as day one of the cycle

Pituitary gland secretes FSH. FSH stimulates the development of a follicle and the production of oestrogen by a follicle Oestrogen stimulates proliferation of the endometrium preparing it for implantation. Oestrogen also affects the consistevu of cervical mucus making it more easily penetrated by sperm Peak levels of oestgen stimulate a surge in the secretion of LH. This surge in LH triggers ovulation High levels of oestrogen inhibit FSH production preventing further follicles from developing. This is negative feedback

In the luteal phase the follicle develops into a corpus luteum. This secretes progesterone Progesterone stimulates vascularisation of the endometrium preparing it for implantation is fertilisation occurs. Progesterone inhibits FSH and LH production. The lack of LH leads to the degeneration of the corpus luteum. This leads to a decrease in progesterone levels which trigger menstruation If fertilisation does occur the corpus luteum does not degenerate and progesterone levels remain high