Function of the Heart
The heart is a muscular, hollow organ that functions as the central pump of the circulatory system. It continuously pumps blood throughout the body, supplying tissues with oxygen and nutrients while removing carbon dioxide and metabolic waste. In adults, the heart is located in the chest cavity between the lungs and beats approximately 60–100 times per minute at rest.
The human heart has four chambers: the right atrium, right ventricle, left atrium, and left ventricle. The atria receive blood, while the ventricles pump blood out of the heart. The right and left sides are separated by a muscular septum, preventing the mixing of oxygenated and deoxygenated blood.
The right side of the heart receives deoxygenated blood from the body through the superior and inferior vena cava. This blood enters the right atrium and then passes through the tricuspid valve into the right ventricle. The right ventricle pumps the blood through the pulmonary artery to the lungs. In the lungs, carbon dioxide is removed and oxygen is added to the blood.
The left side of the heart receives oxygen-rich blood from the lungs through the pulmonary veins. This blood enters the left atrium and passes through the mitral valve into the left ventricle. The left ventricle then contracts and pumps oxygenated blood through the aorta to all parts of the body.
The heart valves—tricuspid, pulmonary, mitral, and aortic—ensure that blood flows in only one direction and prevent backflow.
The heart also has an electrical conduction system that controls its rhythmic contraction. The sinoatrial (SA) node, often called the natural pacemaker, initiates electrical impulses that cause the atria and ventricles to contract in a coordinated manner.
Therefore, the heart performs two major circulation functions: pulmonary circulation, which sends blood to the lungs for gas exchange, and systemic circulation, which delivers oxygenated blood to the entire body. Through continuous pumping, the heart maintains adequate blood flow and supports the normal functioning of every organ and tissue.
