Placenta develops from:
Chorion frondosum and decidua basalis
Chorion villi and decidua basalis
Chorion frondosum and decidua capsularis
Chorion villi and decidua parietalis
Ans. A. Chorion frondosum and decidua basalis1. The human placenta is of chorioallantoic type, consisting of 2 components:a. The chorion, or outer layers of the chorionic cavity, including:i. The syncytiotrophoblastii. The cytotrophoblastiii. The extraembryonic mesodermb. The allantois, containing the umbilical vessels and 3 foetal blood vessels: 2 arteries and 1 vein.2. The foetal trophoblast invades the endometrium, breaks down the endometrial blood vessels into lacunae, and forms villi around them.3. Thus, the placenta is a materno-foetal unit, with:i. The foetal portion formed by the chorion (chorionic plate)ii. The maternal portion formed by the decidua basalis (basal plate).4. The foeto-maternal interface consists of these opposed layers:i. The chorion frondosumii. Fibriniii. The decidua basalis
Fetus Placenta & Fetal Membrane