menstrual cycle and pregnancy Flashcards
day 1 of menstrual cycle
menstruation starts
uterus lining breaks down for about 4 days
day 4 to 14 ( stage 2 )
uterus lining builds up again into a thick and spongy layer full of blood vessels, ready to recieve a fertilised egg
day 14 (stage3)
egg develops and is released from ovary at day 14 ( ovulation)
stage 4 , day 14-28
wall is then maintained until day 28, if no fertilised egg has landed on the uterus wall by day 28, spongy lining starts to break down and whole cycle starts again
FSH
follicle stimulating hormone
FSH produced in
pituitary gand
what does FSH do (2)
- causes egg to mature in one of the ovaries in a structure called a follicle
- stimulates ovaries to produce oestrogen
oestrogen produced in
ovaries
what does oestrogen do
causes lining of uterus to grow
stimulates release of LH
LH
leutanising hormone
LH produced by
pituitary gland
what does LH do
stimulates release of egg at day 14 ( ovulation)
progesterone produced in
ovaries
what does progesterone do
maintains lining of the uterus during second half of cycle
inhibts release of LH and FSH
what does amniotic fluid do
protects embryo against knocks and bumps
