How the Heart Pumps Blood

Your heart is a pump. With every beat, it pushes blood around your body

and ensures that your cells are supplied with oxygen, nutrients, and everything else

they need to survive. It is quite small – about the size of a closed fist – and,

on average, it beats 100,000 times each day. This animation illustrates what happens when

your heart beats and show how blood flows through it. The right side of the heart is shown

in blue: Blue is used to show blood that is low in oxygen. This is blood that is returning from

its journey around your body. Your heart pumps this blood to your lungs to be refreshed

with oxygen. The left side is red: Red indicates blood that is high in oxygen.