Lecture 31 - Placenta - L ecture 31 Placenta Placenta point is access maternal blood/gas and nutrient exchange Be able to identify location and flow of

Lecture 31 – Placenta Placenta – point is access maternal blood/gas and nutrient exchange  Be able to identify location and flow of both maternal and fetal blood through the placenta Early placental development - Villous = placental disc - Extravillous cells that invade into the uterus (so we see the villous trophoblast when we look at the placent) - Blood locations o Fetal blood inside villi o Maternal blood is in the intervillous space - Trophoblast: main epithelial cell type in the placenta - What separates the maternal and fetal blood (3 layers) o Fetal endothelium (three layers of cells-fetal endothelium)  extravillous trophoblast (EVT) o Two layers of trophoblasts  Cytotrophoblast (CTB) • Stem cells • Proliferative trophoblast  Synctiotrophoblast (STB) • Multinucleated • Immediately surrounded by maternal blood o Extravillous trophoblast – carrying fetal blood; invade uterine wall, go toward maternal spinal arterioles (carrying oxygen blood)  replace maternal