menstural cycle accronym
FOLP
FOLP accronym (menstrual cycle) meaning
follicle grows
oestrogen rebuilds
LH causes release
progesterone preserves
what happens in menstural phase (hormone)
endometrium borken down
hypothal releases GnRH which stimulates pituitary to release FSH + LH
FSH levels rise, growing follicle - release oestrogen
low oestrogen inhibits GnRH = low LH + FSH
what happens in follicular phase
increasing oestrogen - rebuild endometrium
low FSH so only one egg matures
high oestrogen, increases GnRH = increases LH+FSH
what happens in ovulation phase
LH surge - secondary oocyte released
leftover follicle becomes corpus luteum
what happens in luteal phase (3)
corpus luteum releases progesterone
progesterone perserves lining
high oestrogen and progesterone - inhibit GnRH - low LH + FSH (could be preganant so no need)
what happens if no fertilisation
corpus leutum breaks down
progesterone + oestrogen levels fall
what happens hormone wise if there is fertilisation
embryo makes hCG
hCG perserves corpus luteum so progesterone stays high and no period happens
simple simple what is acrosome reaction
access for sperm
simple simple what is cortical reaction
close the door
3 steps of acrosome reaction
sperm swims to secondary oocyte (zona pellucida)
acrosome fuses on membrane
enzymes released digest a hole through zona pellucida
3 steps for cortical reaction
sperm membrane fuses with egg, calcium ions flood thorugh egg cytoplasm
causes cortical granules to burst open
release chemicals that harden zona pellucida, destroy sperm receptors on egg surface
how to remember acrosome / cortical
A before C
acrosome - access for sperm
cortical - close the door
differences between oogenesis + spermatogenesis (3)
oogenesis produces polar body, s does not
o starts before birth, s during puberty
o ceases at meonapuse, s till death
