Five Cardinal Manifestations of Inflammation:
- Decreased Function
Stage I: Vascular Responses
- Injured tissues and leukocytes secrete seratonin, histamine, kinins that constrict blood vessels and dilate arterioles causing redness and warmth in the tissues.
- Blood flow increases (hyperemia) and edema forms at the site of injury or invasion. Increased blood flow also bring more nutrients to the injured tissue.
- Capillary leak occurs - plasma leaks into tissues causing more swelling (protective as it forms a cushion. it also dilutes toxins and organisms in the area) and pain (protect the area from further injury by discouraging anymore stimulation).
- Subsides in 24-48 hours.
Stage II: Cellular Response
- Increased numbers of neutrophils or Neutrophillia occurs.
- Arachidonic acid (AA) cascade starts to increase the inflammatory response.
- Fatty acids in plasma membranes converts into AA.
- Enzymes including coozygenase converts AA into other chemicals that gets processed into the substances (histamine, seratonin leukotriens, prostaglandins and kinins) that continue the inflammatory response in the tissues.
- Antiinflammatory drugs work by preveningt cycloozygenase from converting AA into inflammatory substance.
Stage III: Repair and Replacement
- WBC induce remaining healthy cells to divide.
- In cells that cannot divide, WBC trigger new blood vessel growth (angiogenesis) and scar tissue formation.