Left Atrium

The left atrium is one of the two upper chambers of the heart. It receives oxygenated blood from the lungs via the pulmonary veins. Located on the left side of the interatrial septum, the left atrium then transfers this blood to the left ventricle via the mitral valve. Its main role is to facilitate filling of the left ventricle by receiving oxygenated blood. When the left ventricle contracts, blood is then propelled throughout the body to deliver oxygen to the tissues. Compared with the right atrium, the left atrium has a thicker, more muscular wall, as it must withstand greater pressure during ventricular contraction.