The outside of the heart - image description

The illustration shows the front of the heart and where tubes (blood vessels) join the heart. Arrows indicate the direction blood flows through these tubes to enter and leave the heart. Some arrows are red to show blood that has oxygen. Some arrows are blue to show blood that needs oxygen.

Above the heart is labelled upper body. Below the heart is labelled lower body. Either side of the heart is labelled lungs. 

Blue arrows (blood that needs oxygen) enter the heart through tubes from the upper and lower body. Red arrows (blood that has oxygen) leave the heart through different tubes to the upper and lower body. 

Blue arrows leave the heart through tubes to each lung. Red arrows enter the heart through tubes from each lung.