The heart

• Circulatory system


  An example of an organ system whose role is to transport oxygen and nutrients to the body's tissues
• Circulatory system


  • Relies on 3 main things: blood, blood vessels, heart
• Blood


  Carries oxygen and nutrients
• Blood vessels


  Hold the blood
• Heart


  Pumps the blood to keep it moving through the vessels
• Path of blood through the heart

  1. Flows into right atrium and left atrium

  2. Flows from atria into ventricles

  3. Flows out of ventricles into pulmonary artery and aorta

  4. Cycle repeats around 70 times per minute
• Atria


  Top chambers of the heart
• Ventricles


  Bottom chambers of the heart
• Valves


  Prevent blood from flowing backwards, ensure blood flows in the right direction
• Pacemaker cells


  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
• Coronary arteries


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