2.2 - Heart and Blood Vessels

• Aorta

  Carries oxygenated blood from the left ventricle around the body
• Vena cava

  Carries deoxygenated blood back from the organs in the body to the right atrium
• Left ventricle

  Oxygenated blood from the left atrium is moved to the aorta when the ventricle contracts
• Pulmonary vein

  Carries oxygenated blood from the lungs to the left atrium
• Right ventricle

  Deoxygenated blood from the right atrium is moved to the pulmonary artery when the ventricle contracts
• Muscular wall

  Contracts to pump the blood
• Pulmonary artery

  Carries deoxygenated blood from the right ventricle towards the lungs
• Septum

  Separates the left and right sides of the heart
• Valves

  Separates blood from the atrium to the ventricles, prevent backflow
• The lungs are specialised for gas exchange as

  • alveoli are large in quantity
  • alveoli are equally spread across the heart by the bronchioles
  • they're protected by the rib cage and intercostal muscles
  • Lungs are large with a high surface area
  • Constant flow of blood for transport of oxygen
• Blood consists of

  • Plasma - yellow liquid which carries white and red blood cells
  • red blood cells - has a biconcave shape and contains haemoglobin, a red pigment that carries oxygen
  • white blood cells - has various shapes, a nucleus and fights diseases
  • platelets - has an important job in blood clotting
• stents work by as a treatment for a person with a blockage in their coronary artery as it widens the artery, allowing for more blood to flow
• Explain the effect of a partly blocked artery on the human body [6 marks]

  • Less flow of blood
  • so less oxygen
  • so less respiration
  • so less muscle contraction
  • leading to chest pain and shortness of breath
• The pacemaker is found in the right atrium
• Lumen is the hollow empty space in veins and arteries