The Heart and Circulatory System
Your heart is a pumping organ that keeps blood flowing throughout your body. Its special valves ensure blood flows in the correct direction and prevent it from flowing backwards. The heart has four chambers: left atrium, left ventricle, right atrium, and right ventricle.
Blood enters the heart through the vena cava and pulmonary vein into the atria. When the atria contract, blood is forced into the ventricles. The ventricles then push blood out through the pulmonary artery and aorta. This creates a continuous cycle as blood flows to organs through arteries and returns through veins.
The heart needs its own blood supply to function. Coronary arteries branch from the aorta and surround the heart, providing it with the oxygenated blood it needs. Other important blood vessels include arteries (which carry blood away from the heart), capillaries (where exchange occurs at tissues), and veins (which return blood to the heart).
Did you know? The heart has its own natural pacemaker! A special group of cells in the right atrium produces electrical impulses that control the heart's rhythm. Some people need artificial pacemakers to help their hearts beat regularly.
