- Begins with first day of menstruation
- menstruation caused by fall in luteal oestrogen, progesterone and inhibin leading to
rise in FSH and LH a day or so later.
- Antral growth proceeds
- Oestrogen, androgens and inhibin rise, FSH falls, LH flattens
- Dominant follicle selection leads to oestrogen rise and surge, positive feedback leads
to surge in FSH and LH
- Ovulation
- Oestrogen, androgen, inhibin levels fall, progesterone rises.
- FSH, LH levels drop through lack of positive
feedback
- Progesterone levels continue to rise depressing gonadotrophin levels.
- At luteolysis progesterone, oestrogen, etc. levels fall and negative feedback effects on
LH and FSH removed.
- Endometrial sloughing
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