The heart is a muscular organ that pumps blood through the body. It has four chambers: two atria and two ventricles.
- The right atrium receives deoxygenated blood from the body through veins, namely superior and inferior venae cavae. It then pumps it into the right ventricle, which pumps it into the pulmonary artery and lungs to pick up oxygen-rich blood returning from the lungs.
- The left atrium receives oxygenated blood from the lungs via the pulmonary veins; it then passes this blood into the left ventricle, which pumps it into the aorta, which then via its branches distributes the blood through smaller arteries.
Learn more about the anatomy of the heart with free labeled diagrams.