My notes

• Platelets


  • Small fragments of cells
  • Allow the blood to clot at the site of a wound to stop bacteria entering through the wound
• Red blood cells


  • Contain haemoglobin
  • Attach to oxygen, delivering it to all body cells for respiration
• White blood cells


  • Protect the body against harmful microorganisms called pathogens
  • Lymphocytes produce antibodies which attach onto pathogens
  • Phagocytes engulf and digest pathogens
• Blood plasma


  A yellow liquid that transports all your blood cells and other dissolved substances around the body
• Waste carbon dioxide


  1. Produced by the cells

  2. Carried to the lungs
• Small, soluble products of digestion

  Pass into the plasma from the small intestine
• Urea


  1. A waste product

  2. Carried to the kidneys

  3. Removed from the blood to form urine