Inflammation 2

• Inflammatory cellular exudate


  Passage of leucocytes to the interstitium of the inflamed area
• Steps of inflammatory cellular exudate

  1. Margination

  2. Rolling

  3. Adhesion

  4. Transmigration (diapedesis)

  5. Chemotaxis
• Margination


  Accumulation of leukocytes along the endothelial surface
• Rolling, adhesion and transmigration

  Mediated by binding of complementary adhesion molecules on leukocytes and endothelial surfaces
• Chemotaxis


  Locomotion of neutrophils & macrophages toward the irritant under the effect of chemotactic factors released in the area of inflammation
• Chemotactic factors


  • Bacterial products
  • Leukotriene B4 (LT-B4)
  • Complement system products C5a
• Phagocytosis


  Engulfment of particulate material (e.g. tissue debris, living and dead bacteria, other foreign particles) by phagocytic cells
• Phagocytic cells


  • Neutrophils and macrophages are the most important phagocytic cells
• Steps of phagocytosis


  1. Recognition and attachment

  2. Engulfment

  3. Killing and degradation of the ingested material
• Opsonization


  Coating of particulate matter by substances referred to as OPSONINS e.g. IgG and C3b
• Engulfment


  Phagocytic cell sends out cytoplasmic processes (pseudopods) that surround the bacteria, which are internalized within a phagosome that fuses with lysosome to form phagolysosome, releasing lysosomal contents (degranulation)
• Killing and degradation of ingested material

  Mediated within phagocytic cells by oxygen dependent and oxygen independent mechanisms
• Local signs of acute inflammation


  • Hotness
  • Redness
  • Swelling
  • Pain
  • Loss of function
• Systemic effects of acute inflammation

  • Fever (Pyrexia)
  • Anorexia
  • Headache
  • Malaise
  • Leucocytosis
• Fate of acute inflammation

  • Resolution
  • Regression and Healing
  • Progression and Spread
  • Chronicity
• Acute inflammatory reaction


  • Dilated blood vessels
  • Acute inflammatory cells (macrophages and neutrophils)
  • Exudate
• Types of acute inflammation

  • Suppurative (Localized: Boil, Abscess, Carbuncle; Diffuse: Cellulitis, Acute suppurative appendicitis, Meningitis)
  • Non-suppurative (Catarrhal, Pseudomembranous, Serous, Fibrinous, Sero-fibrinous, Hemorrhagic, Allergic, Necrotizing)
• Acute suppurative inflammation (Pyogenic or Septic)


  Severe acute inflammation characterized by pus formation
• Causes of acute suppurative inflammation

  • Staphylococcus aureus
  • Pneumococcus
  • Gonococcus
  • Bacillus coli
• Abscess


  Localized suppurative inflammation resulting in the formation of an irregular cavity filled with pus
• Abscess


  • Caused mainly by staphylococcus aureus which produce coagulase enzyme that helps fibrin formation and localize the infection
  • Commonly occurs in the subcutaneous tissue and in any organ as the lung, brain, liver, breast
• Complications of abscess


  • Blood spread: Septicemia, and toxemia
  • Chronicity
  • Lymphangitis and lymphadenitis
• Lymphangitis


  Inflammation of the lymphatic vessels