the heart

• Circulatory system


  An example of an organ system, its role is to transport oxygen and nutrients to the body's tissues
• Components of the circulatory system

  • Blood
  • Blood vessels
  • Heart
• Heart


  • Consists of 4 chambers with thick muscular walls
  • Pumps blood to keep it moving through the vessels
• Path of blood through the heart

  1. Flows into right atrium and left atrium

  2. Atria contract to push blood into ventricles

  3. Ventricles contract to push blood out into pulmonary artery and aorta

  4. Atria refill with new blood

  5. Cycle repeats around 70 times per minute
• Pacemaker cells


  Group of cells in the right atrium that produce electrical impulses to make the heart contract regularly
• Artificial pacemaker


  Small device implanted under the skin above the heart to regulate the heartbeat
• Artery


  Any vessel that carries blood away from the heart
• Vein


  Any vessel that carries blood to the heart
• Arteries can carry deoxygenated blood and veins can carry oxygenated blood
• Coronary arteries


  Small arteries that branch off the aorta to supply the heart muscle with oxygenated blood