2026 PSEA Medical Diagnostic Sonography Complete Practice Test

Blood returning from the lungs is already oxygenated, and it travels through the pulmonary veins into the left atrium. This makes the left atrium the receiving chamber for blood from the lungs. From there, blood moves through the mitral valve into the left ventricle to be pumped to the rest of the body. In contrast, the right atrium collects deoxygenated blood from the body via the vena cavae, and the right ventricle sends blood to the lungs. So the left atrium is the chamber that receives blood from the lungs.