Page 661 - First Aid for the USMLE Step 1 2020, Thirtieth edition [MedicalBooksVN.com]_Neat
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RepRoductive ` REPRODUCTIVE—EmbRyOlOgy RepRoductive ` REPRODUCTIVE—EmbRyOlOgy SectioN iii 617
Placenta 1º site of nutrient and gas exchange between mother and fetus.
Fetal component
Cytotrophoblast Inner layer of chorionic villi. Cytotrophoblast makes Cells.
Syncytiotrophoblast Outer layer of chorionic villi; synthesizes and Syncytiotrophoblast synthesizes hormones.
secretes hormones, eg, hCG (structurally Lacks MHC-I expression chance of attack
similar to LH; stimulates corpus luteum to by maternal immune system.
secrete progesterone during first trimester).
Maternal component
Decidua basalis Derived from endometrium. Maternal blood in
lacunae.
Endometrial vein
Maternal
Branch villus Endometrial artery circulation
Umbilical vein Maternal circulation
(O rich)
2
Umbilical arteries O 2
H O, electrolytes
(O poor) 2
2 Nutrients
Hormones
IgG
Drugs
Fetal circulation Viruses
CO 2
H O
2
Urea, waste products
Hormones Syncytiotrophoblast
Cytotrophoblast
Endothelial cell
Amnion
Chorionic plate
Maternal blood Decidua basalis
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