the heart

• Circulatory System


  The system that circulates blood around the body
• The Heart

  The organ that pumps blood around the body
• The Circulatory System is actually a DOUBLE Circulatory System
• The Heart Contracts to Pump Blood Around The Body
• How the Heart Pumps Blood

  1. The heart walls contract

  2. The blood is pushed into the arteries

  3. The blood flows through the body

  4. The blood returns to the heart

  5. The heart fills with blood again
• The Heart

  • It has a supply of oxygenated blood
  • Arteries branch off the heart to supply it with oxygenated blood
• Pacemaker

  A group of cells in the heart that control the resting heart rate
• How the Pacemaker Works

  1. The pacemaker cells produce electrical signals

  2. The electrical signals spread to the surrounding muscle cells

  3. The muscle cells contract
• Artificial Pacemaker


  A device implanted under the skin with a wire to the heart that produces an electric current to control the heartbeat
• Doctors use a stethoscope to listen to the valves closing in the heart