What is the name of the protective bag that surrounds a developing embryo in the womb?

The protective bag that surrounds a developing embryo in the womb is called the amniotic sac. This structure is crucial because it is filled with amniotic fluid, which provides a cushion for the embryo, protecting it from mechanical shocks, and maintains a stable temperature. The amniotic sac also facilitates fetal movement, promoting musculoskeletal development.

While the placenta is essential for nutrient and gas exchange between mother and fetus, and the chorion is involved in the formation of the placenta, they do not serve the same direct protective function as the amniotic sac. The umbilical cord, on the other hand, acts as a conduit for blood flow between the embryo and the placenta, but it is not a protective structure. Thus, the amniotic sac stands out as the key element providing a safe environment for the developing embryo.