Heart Parts Match these heart parts with their descriptions and/or functions Tools A B chordae tendineae connective tissue strings attached to AV valves to prevent them from inverting septum divides the right and left sides of the heart right atrium where blood first arrives in the heart left ventricle chamber with the thickest wall mitral valve located between LA & LV tricuspid valve located between RA & RV pulmonary SL valve located between RV & pulmonary artery aortic SL valve located between LV & aorta pulmonary artery carries blood from heart to lungs pulmonary vein carries blood from lungs to heart superior vena cava carries blood from upper body to RA inferior vena cava carries blood from lower body to RA pericardial sac parietal pericardium myocardium cardiac muscle layer of heart endocardium lining of the heart aorta largest artery in the body SA node natural pacemaker of the heart AV node part of conduction system located in septum between atria and ventricles apex narrow pointed tip of heart coronary sinus widened area of the coronary vein that empties blood into RA coronary arteries carry oxygenated blood to the myocardium base broad upper part of heart bundle of His part of conduction system located in the interventricular septum Purkinje fibers part of conduction system that stimulate ventricles to contract mediastinum area between lungs where heart is located left atrium receives blood from pulmonary vein right ventricle pumps blood into pulmonary artery