Inflammation II

Outcome of acute inflammation is dependent on:
  • Site of injury (capacity for repair)
  • Type of injury (severity, pathogenic organisms)
  • Duration of injury

Resolution

  • Complete restoration of the tissue to normal after the removal of inflammatory components
  • Erosions and abrasions - injury with basement membrane intact
    • Heal rapidly with complete resolution

Suppuration

  • Formation of pus - neutrophils, bacteria, inflammatory debris
  • Empyema: space filled by pus and walled off

Repair, organisation and fibrosis

  • Organisation: scarring
  • Most likely if:
    • Lots of necrosis
    • Lots of fibrin
    • Poor blood supply
    • Damage goes beyond basement membrane

Chronic inflammation

  • Favoured if:
    • Suppuration, scarring
    • Persistence of injury
    • Infectious agent
    • Type of injury - autoimmune, transplant rejection
  • Characterized by lymphocytes and macrophages

Granuloma

  • Aggregate of epithelioid histiocytes (macrophages)
  • Associated with foreign bodies - endogenous and exogenous
  • Also associated with specific infections e.g. parasites, TB