The Heart structure and systems

• Left side of the heart


  • Much thicker wall
  • Needs to pump more strongly to deliver blood all around the body
• Right side of the heart

  • Just needs to send the blood to the lungs
• Left side of the heart

  Carries oxygenated blood
• Right side of the heart

  Carries deoxygenated blood
• Heart


  • Lies just off centre left by the chest cavity
  • Made of cardiac muscle
  • Filled with blood and constantly pumping
  • Surrounded by an inelastic pericardial membrane to prevent over-distending
• Coronary arteries


  • Lie over the surface of the heart
  • Supply oxygenated blood to the heart muscle (cardiac muscle)
• Coronary arteries become constricted


  • Reduces blood flow to heart muscle
  • Less oxygen and nutrients make it to the muscle
  • May cause angina or a heart attack
• Aorta


  Main artery which takes oxygenated blood from the left side of the heart to the rest of the body
• Pulmonary artery


  Artery which delivers deoxygenated blood between the right side of the heart and the lungs
• Vena cava


  Major vein which returns blood from the body to the right side of the heart
• Pulmonary vein


  Vein which carries blood from the lungs to the heart
• Pulmonary circulation


  1. Deoxygenated blood from the tissues of the body received by the right atrium

  2. Flows into the right ventricle

  3. Pumped from the right ventricle into the pulmonary trunk

  4. Pulmonary trunk carries the deoxygenated blood into the lungs via the right and left pulmonary arteries
• Systemic circulation


  1. Left ventricle pumps oxygen-rich blood into the main artery (aorta)

  2. Blood travels from the main artery to larger and smaller arteries and into the capillary network

  3. Blood drops off oxygen, nutrients and other important substances and picks up carbon dioxide and waste products

  4. Deoxygenated blood then travels from the body, through the posterior vena cava, and enters the heart in the right atrium