Fill in the Blanks HeartOnline version Parts of the heart by Sara Cipriano 1 oxygen right atrium aorta ventricle venae right cavae atrium lungs left Oxygen - poor blood travels through the into the Blood flows into the lower right chamber , called the , and from there it is pumped through the pulmonary arteries into the . Blood picks up and discards carbon dioxide and continues on to the . Oxygen - rich blood flows into the left ventricle , and from there it is pumped through the into the rest of the body's blood vessels .