The heart is a muscular organ located in the chest, responsible for pumping blood throughout the body. It has four main chambers: the two upper chambers called atria and the two lower chambers known as ventricles. The right side of the heart receives deoxygenated blood from the body, while the left side pumps oxygenated blood to the rest of the body. The heart is divided by a wall called the septum, which separates the right and left sides. Blood flows through the heart via valves, including the tricuspid, pulmonary, mitral, and aortic valves, ensuring one-way blood flow and preventing backflow.