Menstrual cycle Flashcards
1
Q
Day 1-4 = menstruation
A
Endometrium is shed as hormonal support withdrawn
2
Q
Day 5-13 = proliferative phase
A
- Pulses of GnRH from hypothalamus stimulate LH and FSH release = induce follicular growth
- Follicles produce oestrodiol and inhibin = suppres FSH so 1 follicle and oocyte mature
- Oestrodiol rises and +ve feedback on hypothalamus = LH rises = ovulation 36 hours after LH surge
3
Q
Day 14-28 = luteal/secretory phase
A
- follicle from which egg relased becomes corpus luteum
- CL produces oestrodiol and prog = peak 1 week later
- Secretory changes in endometrium = stromal cells enlarge, glands swell, blood supply increases
- CL fails if egg not fertilised = prog and oest falls and menstruation follows
