blood composition

• red blood cells function

  contains a pigment called haemoglobin which temporarily binds to oxygen to transport it around the body
• white blood cell function

  some produce antibodies - lymphocytes

  others engulf and digest foreign materials such as bacteria
• platelets function

  main function is blood clotting

  if there is a blood injury to blood vessel, platelets gather at the site of injury and form a blood clot to prevent further blood loss