Question

Which organ is bypassed in foetal circulation?
(A) Heart
(B) Brain
(C) Lung
(D) Liver

Answer 1

Hint: The foetus is the offspring of the organisms that develop inside its parent and originate from the embryo before the birth. This child takes the nutrients and the other compounds needed for its growth from the mother by the use of the placenta.

Complete answer:
The development of the foetus starts from the ninth week from the fertilization till the birth of the baby. The circulatory system in the foetus, mainly the heart forms at the beginning of the development of the embryo. There is the septal hole between the right atrium to the left atrium and this is called as the foramen ovale. This hole helps to pass the blood between the atrium.
After the birth, the foramen ovale closes completely and the valves of the heart start functioning to maintain the pressure. This happens by the growth of the layer called septum primum over the foramen ovale. But the lungs are not developed earlier. And hence foetus take the oxygen and the nutrients for its growth from the placenta and the umbilical cord. The carbon dioxide and the other waste from the foetus pass to the mother and mix in her blood. Hence the lungs are bypassed in the foetal circulation.

Hence the correct answer is option(C)

Note: The blood from the mother moves to the foetus with the help of placenta. This placenta connects to the baby’s liver. Since the liver is not fully developed and some of the blood is utilized for its growth. But a larger part of the blood moves to the inferior vena cava and then it connects to the right atrium for the circulation.