Immune system

• Immune system


  Protects us against pathogens
• Immune system


  • Destroys pathogens and any toxins they produce
  • Protects us in case the same type of pathogen invades us again in the future
• White blood cells


  Involved in the immune system
• How white blood cells destroy pathogensby phagocytosis

  1. White blood cells detect chemicals released from pathogen and moves towards it

  2. The white blood cell (phagocyte) ingests the pathogen

  3. Use enzymes to destroy pathogen
• Phagocytosis


  The process of white blood cells ingesting and destroying pathogens
• How white blood cells destroy pathogens using antibodies

  1. White blood cells detect antigens on the pathogen

  2. White blood cells produce antibodies

  3. Antibodies bind to pathogens

  4. This triggers the pathogens to be destroyed
• Antibodies


  • Extremely specific to one type of pathogen
  • Can remain in the blood for a long time to protect against future infection
• How white blood cells protect against toxins

  1. White blood cells produce antitoxins

  2. Antitoxins bind to toxin molecules

  3. Prevents toxins from damaging cells