mammalian circulatory system

• Mammals have a closed double circulatory system
• Closed circulatory system


  • All blood vessels are connected within a circuit so blood always remains within the blood vessels
• Double circulatory system


  • Blood passes through the heart twice in each circuit
  • One circuit takes blood from heart to lungs
  • Another circuit takes blood from heart to rest of body
• Mammals have a double circulatory system


  To control the pressure of blood flow
• Blood flow to lungs

  At lower pressure to avoid damage to capillaries
• Blood flow to rest of body

  At higher pressure to reach all respiring cells
• Key blood vessels for AQA

  • Coronary arteries
  • Vena cava
  • Pulmonary vein
  • Pulmonary artery
  • Aorta
  • Pulmonary artery
  • Pulmonary vein
  • Renal artery
  • Renal vein
• Coronary arteries


  Supply heart muscle with oxygenated blood
• Vena cava


  Vein that brings deoxygenated blood to the heart
• Pulmonary vein


  Vein that brings oxygenated blood from lungs to heart
• Pulmonary artery


  Artery that carries deoxygenated blood from heart to lungs
• Aorta


  Artery that carries oxygenated blood from heart to body
• Renal artery


  Artery that carries blood to kidneys
• Renal vein


  Vein that carries blood from kidneys back to heart
• Structure and function of arteries, arterioles, capillaries and veins will be covered in a separate video