BLOOD FLOW THROUGH THE HEART

# The right atrium (RA) receives oxygen-poor blood from all tissues, except the lungs, throughthe superior and inferior venae cavae. Blood flows out of the RA through the tricuspid valve intothe right ventricle.

# The right ventricle (RV) pumps the oxygen-poor blood through the pulmonary semilunar valve
and into the pulmonary artery, which carries it to the lungs.

# The left atrium (LA) receives oxygen-rich blood from the lungs through the four pulmonary
veins. The blood flows out of the LA, through the mitral valve, and into the left ventricle.

# The left ventricle (LV) receives oxygen-rich blood from the left atrium. Blood flows out of the LVthrough the aortic semilunar valve and into the aorta, which carries it to all parts of the body,except the lungs.

# Oxygen-poor blood is returned by the venae cavae to the right atrium and the cycle