Menstrual Cycle Flashcards
What effect do gonadotrophins have on the ovaries?
Promote follicular development and production of ovarian hormones
Why is pulsatile GnRH release important?
Continuous presence of GnRH desensitises receptors so FSH and LH production stops
What hormone is at high levels at the start of the cycle?
FSH
What does FSH do to granulosa cells?
Cause them to produce oestrogen
What effect does high levels of Oestrogen do?
Cause positive feedback, LH surge but FSH inhibition due to Inhibin rising
When does Meiosis 2 start in females?
After ovulation
What happens to the follicle after ovulation?
Becomes Corpus luteum and secretes large amounts of Oestrogen and progesterone (Suppresses LH)
How long does the corpus luteum live (luteal phase)?
14 days
How does the uterus respond to oestrogen?
Endometrium proliferates
How does the uterus respond to oestrogen and progesterone?
Endometrium becomes secretory and forms glands
What happens if fertilization occurs?
Syncytiotrophoblasts produce Human chrorionic gonadotrophin hormone, which has a leutinising effect
What does the corpus luteum do during pregnancy?
Produce steroid hormones until the placenta can do it alone
What 2 phases are in the ovarian cycle?
Follicular and Luteal phase
What 3 phases are in the uterine cycle?
Menses, Proliferative and Secretory phase
