PHILIPPINE SOCIETY OF PEDIATRIC CARDIOLOGY
The normal heart is a muscular pump consisting of four chambers. The two upper chambers, the right and left atria, receive blood returning from the body and lungs. The two lower chambers, the right and left ventricles, are the pumping chambers of the heart. The right ventricle is a low-pressure pump that pushes blood through the lungs, while the left ventricle is a high-pressure pump that pushes blood through the body. The dividing wall between the right and left sides of the heart is called the septum.