The amnion and the chorion are both important membranes that play crucial roles during the development of a fetus, but they have different functions and structures.
The amnion is the innermost membrane that directly surrounds the embryo. It forms a protective sac known as the amniotic cavity, which is filled with amniotic fluid. This fluid provides a cushioning effect, protecting the developing fetus from physical shocks, and allows for movement, which is vital for musculoskeletal development. Additionally, the amniotic fluid helps regulate temperature within the womb.
On the other hand, the chorion is the outermost membrane. It envelops the amnion and is involved in the formation of the placenta. The chorion plays a key role in nutrient and gas exchange between the mother and the developing fetus. It contains villi, which are small, finger-like projections that increase the surface area for this exchange process.
In summary, while both the amnion and the chorion are essential for fetal development, the amnion primarily serves as a protective barrier filled with fluid, while the chorion is crucial for connecting the fetus to maternal circulation and facilitating the exchange of substances.