Placentation in Human Embryology

Okay. Um, good afternoon. Uh, today we are going to be talking about placentation in anatomy embryology. Okay. Uh, why does placentation matter? Um, let's let's start with simple truth. No placenta, no pregnancy. Uh placentation is actually the the the process um uh by which the placenta forms, attaches and function as a life support

system of the developing embryo uh and the fetus. Okay. And um clinically understanding placentation explains ectopic pregnancy, placenta pre, placenta abbrion, preeacclampsia, even fetal growth restriction. So this is not just embryology. It's actually obstetrics in disguise. Okay. So now what is the definition of placentation? Placentation just simply refer to the development okay structure and functional

arrangement of the placenta and its relationship with the uterine wall. Uh it involves the the fetal tissue involve uh that's the coronosum the maternal tissue that is the decidual basalis together they form the placenta. Now let's look at the timeline. When does placentation occur? Uh this is actually very important in fact an

important exam uh uh information. Uh week one fertilization occur right. So there is blastois formation. Week two implantation begins. Now week two to three the trophoblast differentiate. Okay. Week three to four corionic vi develop. Now by the end of the first trimester placenta is well established. So plant placentation is not really a single event actually it is

more like a progressive process. Okay. So now the starting point for implantation is that um uh h implantation cannot occur without implantation. So we say normal implantation site is actually the posterior superior wall of the uterus and what are the structures that implant number one the blastoyst specifically the trophoblast as the placenta