Session 6 - Pregnancy Flashcards
In the third month, what is the arrangement of the villi?
Villi move to only be at the placental end. So chorion frondosum at that end and chorion laeve elsewhere
When does the placenta start to develop
2nd week (first organ!)
In week 2 what structures will there be
Syncytiotrophoblast, cytotrophoblast, bilaminar disk (epiblast and hypoblast)
What happens at day 6
Implantation
What happens at day 9
Blastocyst is embedded in endometrium
Amniotic cavity is formed by the
epiblast
What becomes the umbilical cord?
The connecting stalk
What is the area surrounding the epiblast/hypoblast
Chorionic cavity
What happens to the 3 sacs (chorionic, yolk, and amniotic)
Yolk sac regresses, chorionic gets smaller and amniotic expands
Describe primary secondary tertiary villi
Primary are just outgrowths of trophoblast, secondary mesenchyme has invaded into core, tertiary fetal vessels have invaded mesenchyme core
what does the endometrium transform into in presence of conceptus
decidua capsularis
what happens if the blastocyst can’t implant enough
Placental insufficiency
Compartments of the placenta are called
Cotyledons
How is the villus different in the 3rd trimester
Fewer cytotrophoblast, barrier is thinner
Name hormones produced by placenta
hCG (protein), progesterone and oestrogen (steroid)
How many umbilical arteries/veins
2 arteries (carry deoxy) and one vein (oxy)
When and what is hCG produced by
In first 2 months by synctiotrophoblast
What is choriocarcinoma
Malignancy of chorionic membrane, lots of hCG produced
When does placenta take over progesterone production
11th week
How do progesterone and hCS/hPL influence metabolism
Progesterone increases appetite, hCS/hPL increases glucose availability to fetus
What substance needs facilitated diffusion across the placenta
Glucose
Passive immunity through which Ig
IgG
How are amino acids transferred across placenta
Active transport
How is IgG transferred across placenta
Endo/Exocytosis
