Pathophys Test 2

  1. How does the complement system enhance immune response? (p.14-15)
    • Complement – term for group of plasma proteins that play role in immunity and inflammation
    • Consists of 9 separate proteins – C1-C9
    • Present in inactive forms in plasma
    • Once activated, functions as complement cascade
    • Amplifies immune response once activated by antigen-antibody complex
    • Net effect = formation of cytotoxic complex that helps kill cells
  2. What activates classical pathway? (p.14)
    • Activated by C1 fixation on antibody-antigen complex (IgG, IgM)
    • Image Upload 1
  3. What activates alternate pathway?
    • Initiated by polysaccharides (endotoxins on bacteria IgA)
    • Different set of serum components involved in first 2 steps (properidin P, factors B and D)
    • Activation of C3 occurs in both
    • Net results same – histamine release and chemotaxis
  4. What split products of complement components are referred to as anaphylatoxins? (p.14)
    • C3a and C5a
    • Increase vascular permeability and vasodilation by causing histamine release from mast cells
    • C5a also activates lipoxygenase pathway of arachidonic acid (AA) metabolism in neutrophils and monocytes
    • Also causes release of inflammatory products
Card Set
Pathophys Test 2