Which membrane contains the amniotic fluid?

The amniotic fluid is contained within the amnion, which is a thin but strong membrane that surrounds the developing fetus in the amniotic sac. This fluid plays a crucial role in fetal development, providing a cushioning environment that protects the fetus from physical trauma, allowing for movement, and contributing to the regulation of temperature and the development of the lungs and gastrointestinal tract.

In the context of pregnancy, the amnion is specifically designed to hold this fluid, whereas the chorion is another membrane that forms the outer layer of the amniotic sac but does not contain the amniotic fluid itself. The placenta serves a different function as it facilitates nutrient and waste exchange between the mother and fetus, while the serosa typically refers to the outer lining of the uterus. Thus, the correct identification of the amnion as the membrane containing amniotic fluid highlights its essential protective and supportive role during pregnancy.