mo6

• Circulatory system

  Made up of the heart, blood and blood vessels
• Components of blood in mammals

  • Plasma
  • Red blood cells
  • White blood cells
• Functions of the circulatory system

  • Transports nutrients
  • Transports oxygen
  • Transports carbon dioxide
• Plasma

  The liquid part of blood that carries many substances such as nutrients and carbon dioxide
• Red blood cells

  • Specialised by being biconcave in shape
  • Having no nucleus
  • Containing haemoglobin
  • Allows efficient transport of oxygen in the form of oxyhaemoglobin
• White blood cells

  • Part of the immune system
  • Involved in destroying pathogens
• Types of white blood cells

  • Phagocytes
  • Lymphocytes
• Phagocytes

  Carry out phagocytosis by engulfing pathogens
• Lymphocytes

  • Some produce antibodies which destroy pathogens
  • Each antibody is specific to a particular pathogen
• Heart

  • Made up of four chambers separated by valves
  • Right and left atria and ventricles
  • Right side pumps deoxygenated blood
  • Left side pumps oxygenated blood
  • Left ventricle is thicker than right ventricle to pump blood around body
  • Right ventricle just pumps blood to lungs
• Coronary arteries

  • Heart muscle needs constant supply of oxygen delivered from blood in these arteries
  • If these arteries become blocked, risk of heart attack
• Types of blood vessels

  • Arteries - carry blood away from heart
  • Veins - carry blood into heart
  • Capillaries - connect arteries and veins