Human reproduction, pregnancy, and parturition Flashcards
what are the 4 steps to sexual arousal
EPOR
excitement
plateau
orgasm
resolution
freshly ejaculated sperm are incapable of what
fertilisation
as freshly ejaculated sperm are incapable of fertilisation they must undergo what/where
capacitation in female repro tract
In capacitation the surface of sperm are altered by what
removal of a glycoprotein coat
in capacitation of sperm what does the removal of the glycoprotein coat allow for
sperm to be more permeable to Ca ions
in capacitation what happens to the sperm’s tail
tail movements become more whip like
in capacitation what happens to cAMP levels
levels rise
in capacitation in sperm cAMP levels rise to promote what
acrosomal reaction
what allows for more permeability of Ca ions in capacitation
removal of glycoprotein coat
during penetration of the egg by sperm, what does albumin do
attracts the sperm
during penetration of the egg by sperm, what is released by the mature ovam
albumin
during penetration of the egg by sperm, how do sperm find the egg
they “smell” using an olfactory receptor
during penetration of the egg by sperm, what does fertilin bind to
intergrin
during penetration of the egg by sperm, enzymes in the acrosomal tip allow for sperm to do what
“burrow” through the outer layers of ovum and enter cytoplasm
during penetration of the egg by sperm, what allows the sperm to “burrow” through the outer layers of ovum and enter cytoplasm
acrosomal tip
sperm and egg nuclei fuse to form what
zygote
where does the blastocyst implant
cords of trophoblastic cells
when does the blastocyst develop into an embryo
once it has fully implanted into the cords of trophoblastic cells
what is the placenta derived from
trophoblast and decidual tissue
what do trophoblast cells differentiate into
multinucleate
once trophoblast cells differentiate into multinucleate what does it invade
and what does it form
decidua and breaks down capillaries
forms cavities with maternal blood
once trophoblast cells differentiate into multinucleate what does it invade
and what does it form
decidua and breaks down capillaries
forms cavities with maternal blood
during the development of placenta, the developing embryo sends capillaries into the synctotiotrophoblast projections to form
placental villi
each placental villus forms what
foetal capillaries seperated from maternal blood
what stops the implanted foetus being swept away from the menstrual lining during menstruation
human chorionic gonadotropin (hCG)
what is hCG produced by
produced by the blastocyst
what does hCG do to the life of the corpus luteum
prolongs life of the corpus luteum
after 10 weeks what hormones does the placenta produce
progesterone and oestrogen
what is used in a pregnancy test to detect pregnancy
hCG
morning sickness is caused by
hCG tmay triggers vomiting centre
at the end of the first trimester, what does hCG stimulate
male foetus gonads
produces steroid hormones
why doesnt the placenta secrete oestrogen initially
placenta des not posses the enzymes needed for oestrogen synthesis in the 1st trimester
what enzymes are needed for the placenta to produce enzymes needed for secretion of oestrogen
DHEA (androgen) from foetal adrenal cortex
when is (what trimester) oestrogen and progesterone secreted by the corpus luteum
1st trimester
in pregnancy, oestrogen stimulates the growth of what
myometrium musculature
why does oestrogen stimulate growth of the myometrium musculature
to expel foetus during labour
in pregnancy, what does oestrogen stimulate growth development of (expelling milk)
mammary gland ducts
In pregnancy, progesterone supresses contractions of what
uterine myometrium
in pregnancy, what does prgesterone promote
formation of mucus plug
in pregnancy, what does progesterone stimulate development of
mammary milk glands
what does the parathyroid hormone mobilise
maternal Ca2+ for calcification of foetal bones
what does relaxin do in pregnancy
softens cervix
loosens pelvic connective tissue
in pregnancy, what does CRH stimulate
stimulates DHEA production by foetal adrenal cortex
what is partuition
labour
what does parturition require
dilation of the cervical canal
contractions of uterine myometrium - causes expulsion of the foetus
what is softening of cervix caused by (parturition)
caused by relaxin and prostaglandins
breakdown of cervical collagen fibres allow cervix to dilate during labour
what is relaxation of the pelvic bones caused by
relaxin
what promotes uterine contractions
oxytocin
what does prostaglandin promote in labour
promotes foetal passage along the cervix
what hormone promotes passage along the cervix
what feedback loop
prostaglandin
positive
when stage of labour does the rupturing of the amniotic sac occurs
1st stage
in the 1st stage what is the dilation of cervix required
10cm
what stage is the delivery of the baby
how long does it take
2nd stage
30-90 minutes
delivery of the placenta occurs in what stage
delivery of the placenta
what triggers development of the breast
oestrogen
prolactin
progesterone
what does oestrogen do in development of the breast
duct development
what does oestrogen do in development of the breast
duct development
what does progesterone do in the development of the breast
lobule formation
what does prolactin do in breast development
synthesis of enzymes for milk production
what does suckling trigger
neuroendocrine reflex
(suckling) what hormones does the neuroendocrine reflex secrete
prolactin
oxytocin
in suckling what does oxytocin do
milk ejection
stimulates contraction of myoepithelial cells
hastens involution
suppresses LH and FSH secretion
causes positive feedback on the hypothalamus
when oxytocin inhibits FSH and LH what happens
suppresses menstrual cycle
