Circulatory System- Blood

• Which part of the blood carries oxygen around the body?

  Red blood cells
• What is the name for the shape of red blood cells?

  Biconcave disc
• Why is the shape of a red blood cell important?

  It has a large surface area to absorb more oxygen
• What is the red pigment in red blood cells?

  Haemoglobin
• What does haemoglobin do?

  Binds to oxygen to become oxyhaemoglobin in the lungs and releases it in cells
• What part of the blood defends against pathogens?

  White blood cells
• Which type of blood cell doesn't have a nucleus?

  Red blood cells
• Do white blood cells have nuclei?

  Yes
• What is phagocytosis?

  The process in which a type of white blood cell, phagocytes, engulf harmful pathogens to digest them
• Apart from phagocytosis, how else do white blood cells defend against harmful microorganisms?

  They release antibodies and antitoxins
• What are platelets?

  Small fragments of cells without a nucleus
• What do platelets do?

  Help clot blood at wounds to stop bleeding and microorganisms entering
• What can happen as a result of lack of platelets?

  Excessive bleeding and bruising
• What is the name of the liquid in which everything else is carried in the blood?

  Plasma
• Apart from components of blood, what else does blood plasma carry?

  • Nutrients from digestion
  • Urea
  • Carbon dioxide
  • Hormones
  • Proteins
  • Antibodies and antitoxins