HUMAN SYSTEMS QUESTION 1982           L. PETERSON/AP BIOLOGY

               Describe the following mechanisms of response to foreign
        materials in the human body.

			a. The antigen-antibody response to a skin graft from
			   another person.
                  b. The reactions of the body leading to inflammation of 
                     a wound infected by bacteria.
  

  STANDARDS:
  [1 point for each statement]
                         * = additional points occasionally encountered
  ANTIGENS- REJECTION
  Recognition as foreign antigens
  Rejection by Immune System
  Antigens on surface of graft cells         *Surface glycoproteins as Antigens
  Antigens stimulate Antibody production or T-cells
  
  ANTIBODIES
  Lymphocytes - B Lymphocytes
  B Lymphocytes (Antigen Exposure) -> Plasma Cells
  Plasma cells synthesize Antibodies
                              *Antibodies are Globulins (Immunoglobulins)
                                        Types = IgG, A, M, D, E
                                   Antibodies are proteins
                                   Antibodies remain in circulatory system
                                   Antibody structure
  Antibodies circulate to sites needed
  Antibodies precipitate Antigens or complex w/Antigens
  Antibodies make Antigens susceptible to phagocytosis by WBCs
  Antibody variability due to genes / Clonal Selection Theory
  Antibody specificity - broad/narrow
  Antibodies important in both graft rejection and in fighting bacteria, etc.
  
  T - CELLS
  T -cells involved in cell mediated immunity
  Lymphocytes -> T -cells
                              *T -cells:  thymus involvement
                                        as "helper" cells
  COMPATIBILITY
  Tissues / Graft must be compatible / Tissue matching
  Blood groups as examples of compatibility
  Genetic basis of compatibility
                              *Tolerance / Immunosuppression
  MEMORY
  Memory cells
  Secondary Response
                              *Complement = serum
                         proteins acts by Antibody-Antigen Complex
                            complement inactivates or kills bacteria
  
  
  
  WBCS
  WBCs invade inflection site - destroy bacteria or wall-off
  Phagocytosis
                              *WBCs
                    types:  neutrophils, basophils, eosinophils, monocytes;
                                lysosomes in phagocytic WBCs
                         macrophages
                         WBCs from marrow
                         bacterial presence -> WBC production
  PUS/FLUIDS
  Pus = WBCs, Dead Cells, etc,
  Fluids, plasma -> swelling
  Inflammed area = hot (kills bacteria)
  Lymphatic System Filters
  CLOT
  Clot walls-off inflammed area
  Clotting Mechanism - some detail
  DILATION
  Dilation of Blood Vessels increases circulation; WBCs
                              *Histamines -> Dilation
                                Histamines from mast cells
  CHEMOTAXIS
  WBCs accumulate /"message" calls WBCs to inflammed site
                              *Kinin - chemotactic or increases dilation