bio chap. 24

  1. Innate defenses
    • First line of defense
    • Found in all animals
    • Includes: skin, mucous membranes, phagocytic cells, antimicrobial proteins
  2. Invertebrates have:
    Innate immunity
  3. Vertebrates have:
    Innate AND acquired immunity
  4. Interferons
    • Proteins produced by virus infected cells
    • Found only in vertebrates
    • Help other cells resist viruses
  5. Inflammatory response
    • Triggered by tissue damage
    • Disinfects tissues
    • Limits further infection
  6. Lymphatic system
    A network of lymphatic vessels and organs
  7. Lymphatic vessels
    • Collect fluid from body tissues
    • Return is as lymph to the blood
  8. Lymph organs
    • Such as the spleen and lymph nodes
    • Packed with white blood cells that fight infections
  9. Antigens
    Foreign molecules
  10. Active immunity
    Triggered by infection or vaccinations
  11. Passive immunity
    Can be temporarily acquired by receiving premade antibodies
  12. B cells
    • Secret antibodies
    • Mount the humoral immune response
    • Bacteria and viruses
  13. T cells
    • Attack cells infected with bacteria or virus
    • Cell-mediated immune response
  14. Two kinds of lymphocytes
    B cells and T cells
  15. Antigenic determinants
    • Specific regions on an antigen
    • To which antibodies bind
  16. Clonal selection
    Musters defensive forces against specific antigens
  17. Steps of clonal selection
    • Primary immune response
    • Secondary immune response
  18. Primary immune response
    • Produces effector cells
    • Memory cells that may confer lifelong immunity
  19. Antibodies
    Secreted by plasma (effector) B cells into the blood and lymph
  20. Antibody molecule
    • Y-shaped
    • Two antigen binding sites
    • Specific to the antigenic determinants
  21. Helper T cells and cytotoxic T cells
    • Primarily responsible for the cell-mediated immune response
    • Helper T cells also stimulate the humoral response
  22. AIDS (Acquired Immunodeficiency Syndrome)
    • Results from infection by HIV (human immunodeficiency virus)
    • Attacks helper T cells
  23. The immune system normally reacts:
    • Only against nonself substances
    • Not against self
  24. Transplanted organs:
    • Can be rejected by the body
    • Donors are used that most closely match the patients tissues
    • Transplants between identical twins don't usually have this problem
  25. Autoimmune disease
    • The immue system turns against the body's own molecules
    • Examples include: Lupus, rheumatoid arthritis, Insulin-dependant diabetes mellitus, Multiple sclerosis
  26. Immunodeficiency diseases
    • Immune components are lacking
    • Recurrent infections are frequent
  27. The immune system may be weakened by:
    • Physical stress
    • Emotional stress
    • Students are more likely to be sick during the week of finals
  28. Allergies
    Hypersensitive (exaggerated) responses to antigens (allergens) in our environment
  29. Allergic rxns typically occur:
    Very rapidly in response to tiny amounts of an allergen
  30. Parts of the body where allergic rxns occur:
    • Nasal passages
    • Bronchi
    • Skin
  31. Antihistamines
    • Interfere with histamine's action
    • Provide temporary relief
    • Often make people drowsy
  32. Anaphylactic shock
    • Extreme, life-threatening allergic rxn
    • Can be treated with injections of epinephrine
Card Set
bio chap. 24
bio chapt. 24 exam..the immune system