Coordination and response: The menstrual cycle Flashcards
how long is an average menstrual cycle
1 month
what happens in the middle of the menstrual cycle
event called ovulation, release of a mature egg cell (ovum)
where are the eggs released monthly
ovaries
AKA fallopian tubes, where eggs pass along these tubes and fertilisation occurs here
oviducts
AKA womb, where a foetus develops
uterus
where the entrance to the uterus is
cervix
where the sperm are received during intercourse and where babies pass through during birth
vagina lel -_-
Day 1-5 of the cycle
menstruation: bleeding as uterus lining is shed
Day 6-13 of the cycle
new uterus lining develops and new ovum starts to mature in the ovary)
repair of the endometrium ready for a fertilised ovum
Day 14 of the cycle
ovulation: ovum shed from ovary and can be fertilised in next 2/3 days then dies if not fertilised within 5/6 days
Day 15-19 of the cycle
ovum in fallopian tube, growth of endometrium
day 15-28 of the cycle
blood supply develops in new uterus lining
day 0-7: pituitary hormones, hormones from ovary, follicle, uterus wall
FSH peaks LH normal
oestrogen and progesterone pretty normal
growth of follicle
bleeding
day 7-14: pituitary hormones, hormones from ovary, follicle, uterus wall
FSH falls LH increases to peak at end of this time period
oestrogen peaks to slow down production o FSH, progesterone normal
maturing of ovum and start of ovulation
growth of lining
day 14-21: pituitary hormones, hormones from ovary, follicle, uterus wall
LH from peak to falling quickly and FSH normal
oestrogen starting to fall and progesterone beginning to peak preventing release of LH and FSH to stop another ovulation too quickly
ovulation beginning to end, corpus luteum grows
lining getting very thick
day 21-28: pituitary hormones, hormones from ovary, follicle, uterus wall
LH and FSH low and level
oestrogen gradually falling progesterone quickly falls low
corpus luteum grows breaks down
lining darkens and thickens
what does the corpus luteum do
makes progesterone, which completes the development of the uterus lining so its ready for the fertilised egg
what happens to the corpus luteum when an egg is not fertilised
breaks down and stops making progesterone, if the egg is fertilised however then it carries on living and making progesterone, later on in pregnancy the placenta secrets progesterone taking over the role of the corpus luteum