What is the amniotic sac described as?

• A. A bag of waters that surrounds the developing fetus
• B. The placenta
• C. The umbilical cord
• D. The cervix

Answer: (A)

The amniotic sac is a protective, fluid-filled membrane that surrounds the developing fetus inside the uterus. It consists of the amnion and chorion and is filled with amniotic fluid. This fluid cushions the fetus, helps regulate temperature, and allows for free movement, all of which support healthy development. Because the sac is basically a bag filled with water-like fluid, it’s commonly described as a “bag of waters.” When labor begins, the membranes may rupture and the fluid is released. By contrast, the placenta is the organ that exchanges nutrients and wastes between mother and fetus, the umbilical cord carries blood between the fetus and placenta, and the cervix is the opening of the uterus that dilates during labor.