General Pathology

Introduction

• The term pathology is derived from:
  • Pathos, or suffering
  • Logos, or reasoning/logic.
• There are several definitions of "pathology":
  1. The science of the study of disease.
  2. The scientific study of disease that is concerned with the abnormal states of the body, with the functional disorders that accompany these states, and with the agents and mechanisms that bring them about.
  3. The study of disease including:
     • Aetiology - causal factor(s)
     • Pathogenesis - the development of the disease within the body.
     • Lesions - the observable structural changes in the tissues and fluids of the body.
     • Pathophysiology - the functional changes in diseased tissues.
     • Sequel - the consequences of the disease in the body.
     • Remote effects - the effect of disease in one tissue on other tissues in the body.

Lesions

• Lesions are the abnormalities or changes seen in living tissues due to disease.
• Observed in
  • The live animal
  • Tissues surgically removed from the live animal
    • Bbiopsy/ excision
  • In animals soon after death
    • Necropsy, post-mortem examination.

Decription of Lesions

• Descriptions of lesions is very important
• Whole organs, tissues or individual lesions are described under headings such as
  1. Size
  2. Shape
  3. Colour
  4. Weight - generally referred to body weight
  5. Texture and Consistency
  6. Appearance of the cut surface
  7. Contents of hollow organs
  8. Position, relationships and effects on adjacent tissues