1. Menstrual cycle:- lasts an average of 28 days
- controlled by the brain
- via hormones produced by the pituitary.
- produces GnRH
- which stimulates anterior pituitary
- to secrete FSH + LH into the blood.
3. FSH:- stimulates ovarian follicle growth
- which in turn secretes oestrogen.
- to stimulates the regrowth of the lining of uterus.
4. Early in the cycle:- low level of oestrogen ↓ à inhibits secretion of FSH + LH X.
5. Middle of the cycle:- high levels oestrogen ↑à stimulates a surge of FSH + LH ↑.
- surge of LH à triggers ovulation.
- ruptured follicle à develops into corpus luteum.
- corpus luteum à secretes oestrogen + progesterone.
- high levels of both oestrogen + progesterone levels to drop.
7. At the end of the cycle:- drop in ↓ oestrogen + progesterone blood levels
- causes uterine lining to disintegrate.
- frees pituitary from inhibition
- thus triggering the secretion of FSH + LH,
- which stimulates development of a new follicle.
8. Menstrual cycle:- refers to changes that occur in the uterus
- which begins with menstrual flow phase
- followed by proliferative phase,
- last phase - secretory phase.
9. Ovarian cycle = running parallel to the menstrual cycle- which begins with the follicular phase,
- followed by ovulation
- later, the luteal phase.
10.- are correlated
Changes in the ovary + uterus:
- with the changing pituitary + ovarian hormone levels
- in menstrual cycle.