Heart chamber is a general term used to refer to any of the four chambers of the mammalian heart (an organ): Right atrium: receives oxygen-depleted blood from the body via the superior vena cava and the inferior vena cava and pumps it through the tricuspid valve into the right ventricle. Right ventricle: receives oxygen-depleted blood from the right atrium and pumps it through the pulmonary valve into the lungs via the pulmonary artery. Left atrium: receives oxygen-rich blood from the lungs via the pulmonary veins and pumps it through the mitral valve into the left ventricle. Left ventricle: receives oxygen-rich blood from the left atrium and pumps it through the aortic valve to the entire body via the aorta, including to the heart muscle itself through the coronary arteries. The left ventricle is the thicker of the chambers as it is the chamber that pumps the blood around the body.