Which of the following structures is often referred to as the bag of water?
Correct Answer: C
Rationale: The correct answer is C: Amniotic sac. This structure is often referred to as the "bag of water" because it is a fluid-filled sac that surrounds and protects the developing fetus during pregnancy. The amniotic sac provides cushioning and maintains a stable environment for the fetus to grow. It is essential for the baby's development and acts as a barrier against infections.
Choice A: Urinary bladder - This structure is responsible for storing urine and is not typically referred to as the bag of water.
Choice B: Gall bladder - This organ stores bile produced by the liver and aids in digestion, not related to pregnancy or fetal development.
Choice D: Uterus - While the uterus is involved in pregnancy and fetal development, it is not commonly referred to as the bag of water.