Immune system

Cards (8)

  • First line of defence:
    • Physical and chemical barriers, like the skin
    • Body secretions, like mucus
    • Acid (in stomach)
    • Host defence peptides, like lysozyme (an enzyme)
    • Commensal microorganisms (do no harm)
    • Cillia
  • Second line of defence:
    • Inflammation
    • Phagocytes
  • What is an antigen?

    Cell surface marker that causes and immune response
  • What is an antibody?
    proteins produces by white blood cells
  • White blood cells can:
    • Ingest pathogens and destroy them
    • Produce antibodies to destroy pathogens
    • Produce antitoxins that neutralise the toxins released by the pathogens
  • What happens at part A in phagocytosis?
    The bacterium is engulfed by the phagocyte.
  • What happens at stage B during phagocytosis?
    Enzymes are poured into the food vacuole and the bacterium is destroyed.
  • What happens at stage C during phagocytosis?
    Food vacuole is produced.