All simulations

Human Biology

Heart and Circulation Flow

Follow one drop of blood around the double circulatory system, chamber by chamber.

Read the notes for this topic

Heart and Circulation Flow

Follow one drop of blood all the way around the double circulatory system.

Step 1 of 7

Deoxygenated blood returns to the heart

Blood that has given up its oxygen to the body tissues returns through the vena cava and enters the right atrium. Veins have thin walls, wide lumens and valves to stop backflow.

Goes in

  • Vena cava

Comes out

  • Right atrium