The heart's structure is adapted for efficient blood flow. It has four chambers: the right atrium, right ventricle, left atrium, and left ventricle. Blood flows from the body into the right atrium, then to the right ventricle, and is pumped to the lungs via the pulmonary arteries. Oxygenated blood returns to the left atrium, moves to the left ventricle, and is pumped to the rest of the body through the aorta. The histological structure of the heart includes cardiac muscle fibers, intercalated discs, and a specialized conduction system.
