The maternal endometrium response to trophoblast invasion is called the decidual reaction.
The human placenta is classified as :
Stem villi - or terminal villi, are the region of main exchange, surrounded by maternal blood in intervillous spaces.
The 4 cellular layers separating maternal and fetal blood in sequence are:
Medicine Practicals: Foundations Embryology - BGDA Fertilization to Implantation | Embryo | Fetal | Placenta - BGDB Gastrointestinal | Face and Ear | Sexual Differentiation
General Embryology: Ectoderm Quiz | Mesoderm Quiz | Early Heart Quiz | Placenta Quiz | Respiratory Quiz | Renal Quiz | Genital Quiz