Medical Terminology: Inflammation Quiz

Lecture: Inflammation

• Lecture on inflammation, delivered by Dr. Mohamed M. Metwally, Professor of veterinary pathology, on 20/10/2024.
• Inflammation is a progressive reaction to injury in vascularized tissue.
• Inflammation originates from the Latin word 'inflammare' meaning 'something on fire'.
• Inflammation is a protective mechanism.
• Key purpose of inflammation: to dilute, isolate and eliminate the causative agent; and to repair tissue damage as a result of the injury.

Types of Inflammation

• Acute inflammation: a short-term process (a few hours to days), usually appearing minutes/hours after initial exposure. The process progresses rapidly to resolution or chronic inflammation.
  • Cardinal signs of inflammation (Gross lesions):
    • Redness (rubor)
    • Heat (calor)
    • Swelling (tumor)
    • Pain (dolor)
    • Loss of function (functiolaesa)
  • Microscopic lesions:
    • Vascular congestion
    • Leukocytic infiltration
    • Presence of exudate
• Chronic inflammation: a prolonged process (weeks to years), characterized by chronic inflammatory cell infiltration and fibroplasia.
  • Causes:
    • Failure of the acute inflammatory response to eliminate the causative agent
    • Repeated episodes of acute inflammation
    • Unique biochemical characteristics/virulence factors in causative agents
  • Gross picture:
    • Grey/white color
    • Firm consistency due to fibroblast proliferation and fibrous connective tissue deposition
    • Irregular shape due to haphazard leukocyte accumulation and fibrosis
  • Microscopic picture:
    • Inflammatory cell infiltrate (lymphocytes, macrophages)
    • Proliferation of fibroblasts and deposition of collagen

Classification of Inflammation

• Distribution:
  • Focal (single inflamed area)
  • Multifocal (multiple inflamed foci)
  • Locally extensive (involving a considerable area)
  • Diffuse (involving the entire organ)
• Severity: inflammation can be mild, moderate, or severe based on the extent of injury and tissue damage.
• Duration: inflammation can be peracute, acute, or chronic based on the length of time the process persists.

Types of Inflammatory exudates

• Serous: clear watery fluid, often containing proteins (e.g., albumin).
• Catarrhal: mucous membranes, containing viscous gelatinous fluid.
• Purulent/suppurative: pus-containing exudate, caused by pyogenic bacteria.
• Hemorrhagic: blood-containing exudate.
• Fibrinous: fibrinous exudate (e.g. pseudo-membrane).

Inflammatory Cells

• Acute: Mast cells, neutrophils, eosinophils, basophils.
• Chronic: Macrophages, epithelioid cells, multinucleated giant cells and Lymphocytes.