The structure that connects the fetus to the placenta is called what?

The umbilical cord is the structure that connects the fetus to the placenta, playing a critical role in fetal development. It serves as a lifeline, allowing the transfer of oxygen and essential nutrients from the mother to the fetus, while also facilitating the removal of waste products from the fetal circulation back to the mother's bloodstream. This connection is vital for the fetus's growth and overall health throughout gestation.

The other options represent different structures related to pregnancy but do not serve the same function as the umbilical cord. For instance, the amniotic sac provides a protective environment for the developing fetus but does not facilitate the exchange of substances between the mother and fetus. The chorion is the outer fetal membrane that contributes to the formation of the placenta but does not connect directly to the fetus. The placental membrane, meanwhile, is involved in the exchange processes, but again, it does not provide the physical connection between the fetal and maternal systems like the umbilical cord does.