Final answer:
The placenta is the crucial organ responsible for the metabolic interchange between the mother and the fetus, transferring nutrients, oxygen, and removing wastes.
Step-by-step explanation:
The organ that allows metabolic interchange between the mother and the fetus is the placenta. This temporary but vital organ plays a crucial role in the development of the embryo or fetus during pregnancy.
The placenta facilitates the transfer of oxygen, nutrients, and antibodies from the mother's bloodstream to the fetus. It also enables the removal of waste products, like urea and carbon dioxide, from fetal circulation back into the maternal blood for excretion. Acting as a protective barrier, the placenta ensures that the fetal and maternal blood do not mix, which helps to safeguard the fetus from the maternal immune system potentially recognizing it as foreign.
Blood vessels within the placenta, including the umbilical vein and arteries, form a complex network that supports the efficient exchange of substances. The umbilical vein carries oxygen-rich blood from the mother to the fetus, while the umbilical arteries return depleted blood to the placenta. Despite this exchange, maternal and fetal blood cells do not mix directly because of the placenta's structure, highlighting its significance in maintaining a safe and supportive environment for fetal development.