What is another description of the amniotic sac?

• A. A bag of waters surrounding the fetus
• B. The placenta
• C. The uterus
• D. The cervix

Answer: (A)

The amniotic sac is the protective, fluid-filled membrane that surrounds the developing fetus, which is why it’s often called a bag of waters. It’s made up of the amnion and chorion and contains amniotic fluid that cushions the fetus, allows for movement, and helps keep a stable environment. The other structures have different roles: the placenta is the exchange organ between mother and fetus, the uterus is the muscular housing of the pregnancy, and the cervix is the passage at the bottom of the uterus that opens during labor. The phrase bag of waters captures the idea of the surrounding, fluid-filled sac around the fetus. When labor starts, the sac can rupture, releasing the fluid.