Get to know the functions of your heart, blood vessels, and blood itself and how they work together to maintain your health.

Capillaries are very tiny blood vessels — so small that a single red blood cell can barely fit through them. They help to connect your arteries and veins in addition to facilitating the exchange of ...

Check your knowledge of the heart and how blood is transported around the body by blood vessels ahead of your Higher Human Biology exam. Brush up on your knowledge of arteries, capillaries, veins and ...