Circulatory system - heart

• 2 circuits joined together

  1. The right ventricular pumps deoxygenated blood to lungs to take oxygen.then returned to heart
  2. left ventricular pumps oxygenated blood around all organs then returns to heart deoxygenated to be pumped to lungs
• Valves to stop back flow of blood
• 1. Blood flows into the two atria from the vena cava and the pulmonary vein
  2. atria contracts pushing blood into ventricles
  3. ventricles to pulmonary artery and aorta and out of the heart
  4. blood to organs through arteries and back through veins
• Resting heart rate controlled by a group of cells in right atrium that act as pacemaker
• Artificial pacemaker 


  to control heartbeat if irregular heartbeat produces electrical currents