blood form branches of umbilicar arteries (from intenral iliac) carrying deoxygenated blood.
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Oxygenated
venous blood from placenta passes via umbilical vein to liver (through passed by ductus venosus) adn from there to right atrium
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blood enters intervillous spaces from the
spiral arteries
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what sourt of flow in intervillous space?
countercurrent flow
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blood leaves intervillous spaces via
uteirne arteries
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fetus grows relativley faster than placenta. how
branching of villia nd brush border, decerase in vollois diamate, thinnign of barrier
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What sort of substances concentrated in fetal circulation
Fe, Ca , Cu glucose Vi B12, folate, riboflavin, vit C, aa and hormones etc.
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what confers passive immunity to fetus
immunoglobulins
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what preserves corpus luteums release of progesterone?
hCG
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what prepares for initation of parturition?
oestradiol induces production of contraction-associated proteins by the myometrium
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what does hPL aka human chorionic somatomammotrophin do?
It is similar to GH and PRL- it increases maternal lipid breakdown to provide fetus with energy
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preoparing for and iitation of partuirtiaion
y; • preparing for & initiation of parturition. Oestradiol induces production of contraction-associated proteins by the myometrium, stimulates production of oxytocin receptors; and increases the excitability of the myometrium. Placental CRH (produced
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myometrical contraciton and cervix?
Placental prostaglandins (PGE2 and PGF2) act in this way; (earlier in pregnancy the relaxant prostagla. PGI2 is a relaxamt earleir on
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prep for lactaiton
oestradiol stimulates development of the duct system of the mammary gland; progesterone causes development of the alveoli; hPL has a lactogenic action, developing the secretory potential of the breast alveoli; however, during pregnancy, production of
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Production of estradiol
Although the placenta can produce progesterone from cholesterol, the primate placenta does not have the key enzymes necessary to produce estradiol from cholestero.l (17-hydroxylase; 17
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insteas
Instead it uses the weak androgen dehydroepiandrosterone (DHEA) which is synthesized in the fetal adrenal gland. This is converted by the placenta in part to estradiol. However, it is also 16- hydroxylated by the liver, to yield a steroid which is co
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Other cards in this set
Card 2
Front
function of trophoblast in humans
Back
phusical attachemnt of conceptus to uterus, inasion of endometriual tissue and other ***** tooo
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