All the cells in your body require oxygen to survive. The cells also require a sufficient supply of nutrients. Waste products must be removed from the cells at a rapid rate. Oxygen and nutrients are carried around the body in your blood, which is pumped by your heart.
Oxygen enters your blood stream through the lungs. Waste products such as Carbon Dioxide are eliminated through a process called Gas Exchange. Without a beating heart pumping blood through out our body we develop rapid cell damage.