CPM Certified Professional Midwife

Answer: C - Amnion is the outer layer

The chorion (outer membrane) assists in the formation the chorionic villi, which is connected to the endometrium and gives rise to the placenta. As the chorion develops, it blends with the fetal portion of the placenta. The amnion (inner membrane) blends with the fetal umbilical cord. The following are functions of the amnion:
1. Protects the fetus from loss of heat, and aids in maintaining a constant fetal body temperature
2. Serves as a source of oral fluid for the fetus
3. Separates the fetus from the fetal membranes
4. Protects the fetus from direct trauma by distributing and equalizing the impact on the fetus that is experienced by the mother