The Placenta at 22 weeksFetal and Maternal Surfaces
What are the major functions of the Placenta?
Provide fetus with nutrients
Fetal kidneys don’t function for excretion yet, so use placenta
Blood from mom contains oxygen and is carried to the embryo/fetus through the placenta
Exchange of hormones through blood to maintain pregnancy
Blood Flow in Placenta
Maternal blood enters the intervillous space from the endometrial arteries in the decidua basalis. Blood is discharged in the intervillous space. The large space is drained by endometrial veins that also penetrate this area. The numerous branch chorionic villi are continuously showered with maternal blood that circulates through the intervillous space.
Blood Flow in Placenta Continued
Fetal cells can breech the placental membrane and have been found in the mother.
Fetal cells can populate various organs in the mothers body. May later help to repair damaged or diseased organs.
Advantage: isolate the fetal cells from mothers blood and sequence the genome – could be used to detect any congnital defects
Anatomy of Umbilical Cord
Normal umbilical contains:
Two arteries (de-oxygenated)
One vein (oxygenated)
Embedded within loose, proteoglycan rich matrix (Wharton’s jelly)
Substance is resistant to twisting and compression
Property of the umbilical cord is to protect the critical vascular lifeline between the placenta and the fetus
Cross-Section of Umbilical Cord
Normal vs. AbnormalUmbilical Cords