THORAX ABDOMEN AND PELVIS

Detailed explanation-1: -Inside the fetal heart: Blood enters the right atrium, the chamber on the upper right side of the heart. When the blood enters the right atrium, most of it flows through the foramen ovale into the left atrium.

Detailed explanation-2: -The foramen ovale is an aperture in the muscular tissue between the left and right atrium that allows blood to cross the atria and bypass pulmonary circulation during fetal development. The surrounding tissue is composed of smooth muscle derived from the septum primum and septum secundum.

Detailed explanation-3: -Blood flow in the unborn baby follows this pathway: Oxygen and nutrients from the mother’s blood are transferred across the placenta to the fetus through the umbilical cord. This enriched blood flows through the umbilical vein toward the baby’s liver. There it moves through a shunt called the ductus venosus.

Detailed explanation-4: -The inferior vena cava blood enters the right atrium, and approximately 40% is diverted to the left atrium through the foramen ovale.