Inflammation - Introduction

()Map GENERAL PATHOLOGY (Map) INFLAMMATION

Introduction

• Inflammation is the process by which cells and exudate accumulate in irritated tissues and usually tend to protect them from further injury.

Cardinal Signs

• The classical gross signs of inflammation have been recognised since the time of Celsus (25BC-AD50).
  • These are known as the cardinal signs of inflammation.

1. Reddening
   • Caused by increased blood flow (hyperaemia) to the area, due to dilation of previously inconspicuous capillaries..
2. Swelling
   • The inflamed area appears swollen due to exudation of fluid from the dilated blood vessels into the inflamed tissue.
3. Heat
   • There is increased heat in the affected tissue due to increased blood flow.
   • The temperature of the inflamed portion approximates to internal body temperature.
4. Pain
   • Chemical mediators of pain are release by damaged tissue. in the affected tissue caused by #* Inflammatory exudate puts local pressure on nerve endings.
5. Loss of function
   • The pain and damage to the tissue result in a reluctance to use the inflamed portion.

Causes

• Inflammation has many causes:
  • Microorganisms and helminths (parasites).
  • Trauma
  • Mechanical, thermal, and chemical agents.
  • Some immune reactions
    • Hypersensitivity/ allergy.
  • Malignant neoplasms.