Heart beating

Heart beating

The heart gets messages from the body that tell it when to pump more or less blood depending on a person's needs

When you sleep

when you're sleeping, it pumps just enough to provide for the lower amounts of oxygen needed by your body at rest. 

When you are excersicing

the heart pumps faster so that your muscles get more oxygen and can work harder.

Heart beating

How the heart beats is controlled by a system of electrical signals in the heart. The sinus (or sinoatrial) node is a small area of tissue in the wall of the right atrium. It sends out an electrical signal to start the contracting (pumping) of the heart muscle.