Orris

Defenation of inflammation

Reading File
Finding Sources
Finding Sources
Reading File
Inflammation is defined as a protective response of vascularized tissues to injury or infection, designed to deliver leukocytes and molecules of host defense from the circulation to the affected site.
Key points from the definition (Robbins & Cotran, Pathologic Basis of Disease):
  • Purpose: Although commonly perceived as harmful, inflammation is actually an essential, protective response for survival. It functions to rid the body of both the initial cause of injury (e.g., microbes, toxins) and the consequences of that injury (e.g., necrotic cells and tissue).
  • Mediators: The defense is carried out by phagocytic leukocytes, antibodies, and complement proteins, most of which circulate in the blood in an inactive state until recruited to a site of need. Some sentinel cells reside in tissues, constantly on watch for threats.
  • Consequence of absence: Without inflammation, infections would spread unchecked, wounds would fail to heal, and damaged tissues could become permanent, festering injuries.
  • Terminology: The suffix -itis added to an organ name denotes inflammation of that site (e.g., appendicitis, conjunctivitis, meningitis).
Sequential steps of a typical inflammatory reaction:
  1. Recognition of the noxious stimulus (via receptors on sentinel cells like macrophages and dendritic cells that detect microbial products or damage signals).
  2. Recruitment of leukocytes and plasma proteins from the blood into the affected tissue.
  3. Removal of the stimulus, primarily via phagocytosis of microbes and dead cells.
  4. Regulation of the response to terminate it once its purpose is achieved.
  5. Repair of the damaged tissue through regeneration of surviving cells and/or scarring (connective tissue deposition).
  • Robbins, Cotran & Kumar Pathologic Basis of Disease, p. 81
This is a shared conversation. Sign in to Orris to start your own chat.