Which organ stores and nurtures a developing fetus during pregnancy?

• A. Vagina
• B. Uterus
• C. Ovaries
• D. Cervix

Answer: (B)

The uterus is the organ that stores and nurtures a developing fetus during pregnancy. It is a hollow, muscular chamber whose inner lining, the endometrium, thickens and supports implantation of a fertilized egg. As pregnancy progresses, the placenta forms partly from uterine tissue and maternal blood, delivering oxygen and nutrients to the fetus and removing wastes. The muscular wall, or myometrium, expands to accommodate growth and then contractions of the uterus help drive birth.

Other structures don’t serve this role: the vagina is the birth canal and passage for the baby; the ovaries produce eggs and hormones but do not house a developing fetus; the cervix is the narrow opening that protects the uterus during pregnancy and opens during labor.