Heart

Right Atrium

Receives deoxygenated blood returning from the body through the superior vena cava, inferior vena cava, and coronary sinus.

Left Atrium

Receives oxygenated blood returning from the lungs via four pulmonary veins.

Role of Atria

Thin-walled receiving chambers that collect blood and pump it down into the ventricles.

Right Ventricle

Pumps deoxygenated blood out to the lungs through the pulmonary artery (and pulmonary trunk) for oxygenation.

Left Ventricle

The largest and thickest-walled chamber; pumps oxygenated blood out to the rest of the body through the aorta.

Role of Ventricles

Thick, muscular pumping chambers that generate the pressure needed to circulate blood.

Septum

A wall of muscle that separates the left and right sides of the heart, preventing oxygenated and deoxygenated blood from mixing.