Placenta and Fetal Membranes Flashcards
Week 1, what do we have?
what gives rise to the embryo?
what gives rise to the placenta?
1 cell layer and inner cell mass
inner cell mass
trophoblast
in week 1, what do trophoblasts give rise to cellularly?
Cytotrophoblast
Syncytiotrophoblast
What is the job of Cytotrophoblasts?
syncytiotrophoblasts?
mitotically active stem cell layer that give rise to cells of the placenta –> also gives rise to the syncytiotrophoblasts
secrete enzymes that you can erode into the endometrial lining and it is going to release hCG for initial signal of pregnancy
what day do we get implantation?
day 6
Week 2, what is our embryo?
what comes from the epiblast?
bilaminar disc –> epiblast and hypoblast
primordial germ cells, also the amnion forms to make the amniotic cavity that will be filled with fluid.
Decidua Reaction?
as the syncytiotrophoblast erodes into the endometrial lining, we get this.
it’s changing the endometrium, breaking up the endometrium decidua cells and when you lyse that you now have glycogen and nutrients to help nourish the embryo and helps provide immunologically privileged site so mom doesn’t reject foreign tissue.
What does the hypoblast give rise to in week 2?
what are the different layers of it?
extraembryonic mesoderm –>
somatic extraembryonic mesoderm –> lines trophoblast and amnion
extraembryonic splanchnic mesoderm –> lining yolk sac
What is derived from extraembryonic mesoderm?
what is coming from each?
Connecting stalk –> coming from somatic mesoderm –> becomes umbilical cord
Chorion –> coming from extraembryonic somatic mesoderm, cytotrophoblast, syncytiotrophoblast
what is the chorion?
layer of placenta
Hydatidiform mole?
what is it caused by?
what are you going to see?
abnormal growth of the trophoblast
abnormal proliferation of the syncytiotrophoblast and cytotrophoblast and remember syncytio is making hCG so you’ll have a ton of hCG.
2 types of hydatididiform moles?
in both cases, what’s going to keep on growing?
clinical presentation?
what can happen because of this mole?
1) complete mole –> empty oocyte.. so fertilization of an empty oocyte followed by duplication of sperm. so cloning of one sperm
Partial –> fertilization of an empty oocyte by 2 sperm
2) Partial mole –> 2 sperm fertilize a normal egg.. zona reaction did not occur for polyspermy to be prevented.
vaginal bleeding, pelvic pressure or pain, enlarged uterus, morning sickness
Choriocarcinoma
hydatidiform mole.. DNA test what would you get?
100% paternal because oocyte is empty
Placenta has 2 parts, what is it?
what are each coming from?
fetal part and maternal part
fetal part from Amnion and Chorionic Sac
maternal part from the Decidua basalis and Decidua Capsularis
Amnion is coming from what?
when is it formed?
where did it come from?
ectoderm
2nd week
epiblast
Amniotic fluid?
what is it composed of? what are the particulates?
functions?
specific need for development?
composed of ions, glycophospholipids, steroids, particulates (cells of the embryo)
cushion against injury, maintains temperature, ease of movement, diagnostic information.
lung development and GI development.
Amniotic fluid 3 sources of amniotic fluid?
Cells of the amnion
maternal blood
fetal urine
Amniotic fluid once its formed happens to do what with the fetus?
fetal swallowing..
this primes the GI system –> goes into fetal blood –>
1) carried by umbilical arteries to the placenta and the waste will be exchanged
2) carried to fetal urine –> and that contributes to more amniotic fluid.
Oligohydramnios?
3 causes?
too little amniotic fluid
renal agenesis (can’t produce amniotic fluid)
Placenta insufficiency (can’t make as much maternal blood and less amniotic fluid
premature rupture of the amnion.