Placenta and Membrane
The placental membrane separates maternal blood from fetal blood. The maternal component of the placenta is known as the decidua basalis. Oxygen and nutrients in the maternal blood in the intervillous spaces diffuse through the walls of the villi and enter the fetal capillaries. The two chorioamniotic membranes are the amnion and the chorionic, which make up the amniotic sac that surrounds and protects the fetus. The placenta functions as a fetomaternal organ with two components: the fetal placenta (Chorion frondosum), which develops from the same blastocyst that forms the fetus, and the maternal placenta (Decidua basalis), which develops from the Chorion refers to the outermost membrane surrounding an embryo of a reptile, bird, or mammal while placenta refers to a temporary organ that connects the developing fetus via the umbilical cord to the uterine wall in placental mammals. Thus, this explains the main difference between chorion and placenta maternal uterine tissue.