Anatomy of the placenta
In order to understand the chronological development of the chorionic villi it is important to have a comprehensive overview of placental anatomy. In this diagram, the placenta is roughly four months old and various fundamental structures can be recognized, namely the umbilical cord, the amnion, the chorionic plate, the already advanced branching of the villi, the basal plate and the cotyledon.
At birth, the placenta consists of two parts:
- maternal portion
- fetal portion