Fill in the Blanks HeartOnline version Parts of the heart by Sara Cipriano 1 aorta atrium atrium oxygen right venae cavae lungs left ventricle right 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 .