pregnancy Flashcards
what happens in early pregnancy for the endometrium
maintained in the secretory phase by estrogen and progesterone
the form the early embryo takes before implanting into the endometrium
the blastocyst
fertilized egg
zygote
the future embryo
inner cell mass of blastocyst
blastocyst hatching
last step before embryo can attatch to endometrium where blastocyst breaks out of ZP
when does uterine implantatin occur
6-7 days following fertilization
ectopic pregnancy
embryo implantation anywhere but uterus. cannot be carried to term
what does the trophoblast do
enzymatically invades the endometrium
decidua
endometrium
surface layer of cells of blastocyst
trophoblast
why does the tropoblast enzymatically envade the endometrium
to release nutrients and begins process of placenta development
what do the tropoblast cells secrete
hormone hCG at high concentrations
what is hCG
pregnancy hormone
where is hCG also found
in urine and is the basis for the early pregnancy test
what is the function of hCG
prevent menstruation and support early stages of pregnancy
what is hCG similar to
LH and binds to its receptor
what does LH do for hormone production of CL
sustains hormone production before fetus and placenta take oevr estrogen and progesterone production
when does the fetus and placenta take ove restrogen and progesterone production
after 3 months
what does hCG do with men
binds to LH receptors of leydig cells in the embryonic testis to stimulate testosterone production (wollfian ducts) (+DHT = male external genitalia)
how long is the human gestation period
38 and 40 if you count 2 weeks since last menstrual period
what happens at 8 weeks
human form and organ systems are established- embryo to fetal transition
where does the human fetus develop
within the amnionic aac
what is the amnion
fetal membrane developed from extra embryonic tissue that grows with the fetus eventually filing the uterine cavity filled with amnionic fluid
amnionic fluid purpose
swallowed and urinated by fetus. provides buoyant chamber, allows for free movement, barrier to infection, temp control, stops adhesion to amnion
what does the umbilical chord transport blood between
the fetus and placenta
umbilical chord made up of
filled with tough but flexible connective tissue (whartons jelly) and 1 vein and 2 arteries
umbilical arteries
deoxygenated blood and waste from fetus to placenta
what does the mature placenta do
support gas, nutrient, waste exchange between fetal and maternal blood
what is outside the amnion
chorionic membrane
chorionic membrane structure
smooth and villous surfaces (placenta)
purpose of chorionic villi
provide massive SA for metabolic exchange
150 mL of maternal blood exchanged at placenta 3-4 times per min
some float in maternal blood and some invade further to attatch to maternal lining anchoring placenta
what is exchanged at the placenta
-ox delivered, co2 removed
-carb, FA, AA, vit, minerals, ions
-waste removal or uric acids, bilirubin
-passive and facilitaed diffusion, active transport, pinocytosis
-some chemicals like recreational drugs and viruses cross the placenta
functions of placenta
hormone production, exchange listed before, anchoring vili provide structural integrity against placental loss, transfer of some immunoglobulin antibodies to fetus, prevents fetal rejection as foreign antigens
hormone production, anchorage, immunity, immunomodulatory
