Learning Center Articles

Inflammation : Vascular response

Inflammation

  • Sequential response to cell injury that:
    • Neutralizes and dilutes inflammatory agent
    • Removes necrotic materials
    • Establishes an environment suitable for healing and repair
  • Inflammatory response can be divided into
    • Vascular response
    • Cellular response
    • Formation of exudate
    • Healing

Vascular response

  • After cell injury, arterioles in area briefly undergo transient vasoconstriction
  • After release of histamine and other chemicals by injured cells, vessels dilate, resulting in hyperemia
  • Vasodilation chemical mediators
    • Increased capillary permeability
    • Movement of fluid from capillaries into tissue spaces
  • Fluid in tissue spaces
    • Initially composed of serous fluid
    • Later contains plasma proteins, primarily albumin
      • Proteins exert oncotic pressure that further draws fluid from blood vessels
      • Tissue becomes edematous
  • As plasma protein fibrinogen leaves blood, it is activated to fibrin by products of injured cells
  • Fibrin strengthens blood clot formed by platelets
  • In tissues, clot traps bacteria to prevent spread