1. Vascular changes
   1. Neurogenic antidromic reflex inhibits vasocontriction and contributes to vasodilation
   2. increased permeability
      1. Histamine
         1. mediated endothelial cell contraction on small venules
      2. Serotonin
      3. Arachondonic metabolites
         1. Prostaglandins
         2. Leukotrienes
      4. Cytokines
         1. TNF and IL 1
            1. Junctional retraction in venules, 4-6 hours after injury lasts for 24hrs
   3. Exudate
      1. Serous-only contain albumin from serosal mesothelial cells
      2. Purulent-type of liquifactive, contains pus
      3. Sanginous-contains RBCs
      4. fibrinous-severe inflammation, precipitated fibrin arranges in strands and bands
      5. migration of leukocytes through vessel calls during inflammation into adjacent tissues in main cellular phase of acute inflammation
2. Associated cells
   1. PMNs
      1. First to appear, faster and more numerous
         1. chemotactic factors: bacterial products, C5a, Leukotriene B4, chemokines
   2. macrophages
      1. release IFNgamma, promotes macrophage activation and epitheloid cell formation
   3. lymphocytes
   4. plasma cells
3. Acute
   1. Increased blood flow
   2. swelling
   3. impaired function
   4. redness
   5. heat
4. Chronic
   1. Non specific chornic inflammation
      1. Example: Ulcer
      2. no characteristic pattern of tissue reaction. Most cells are monocytes, lymphocytes and plasma cells
   2. Granulomatous inflammation
      1. focal arrangement of tissue, isolate affected site
      2. Epitheloid cells
         1. Form Giant cells near center of granuloma