Blood Flow

• pushes blood through the tricuspid valve into the right ventricle

Right Atrium

• the right ventricle pumps blood through the pulmonary semilunar valve into the pulmonary trunk

• the pulmonary trunk is a big vessel that splits to form the left and right pulmonary ateries

Right Ventricle

• the blood goes through the pulmonary arteries and travels to the lungs to be oxygenated

Pulmonary arteries

The oxygen-rich blood is pumped back through the heart and out to the rest of the body through this pathway:

• the blood gets back to the heart through the 4 pulmonary veins, traveling toward the inside of the relaxed left atrium

• the left atrium contracts so that blood moves down the through the mitral valve into the left ventricle

• the left ventricle flexes to increase blood pressure, causing blood to go through the aorta (largest artery), which sends oxygen-rich blood out to the rest of the body.

Left Ventricle

• after the organs receive the oxygen and nutrients they need, the blood travels through the veins, back to the heart and the process starts over.

Pulmonary arteries