Introduction to Pathology and Cellular Pathology Study Notes

INTRODUCTION TO PATHOLOGY

  • Pathology studies structural, biochemical, and functional changes in cells, tissues, and organs related to disease.
  • Serves as a bridge between basic sciences and clinical medicine.

CLASSIFICATION OF PATHOLOGY

  • Divided into:
    • General pathology: Common cellular responses to injury.
    • Systemic pathology: Alterations in organ systems.

ASPECTS OF DISEASE PROCESS

  • Etiology
  • Pathogenesis
  • Morphological changes
  • Clinical manifestations

ETIOLOGY

  • Initiating cause of disease, classified into:
    • Genetic factors (mutations, polymorphisms)
    • Environmental factors (infectious, nutritional, chemical).
  • Diseases often result from multiple etiological factors.

PATHOGENESIS

  • Sequence of events leading to disease development, and explains how etiologies produce disease manifestations.
  • Central to pathology and underlies precision medicine.

MORPHOLOGY

  • Structural changes in cells/tissues diagnostic of disease.
  • Morphological analysis is central in diagnostic pathology, supplemented by genetic studies.

CLINICAL MANIFESTATIONS

  • Result from genetic, biochemical, and structural changes, leading to functional abnormalities and clinical outcomes.

CELL INJURY RESPONSES

  • Injuries occur when adaptive limits are exceeded or damaging insults arise; injuries may be reversible or irreversible leading to cell death.

CAUSES OF CELL INJURY

  • Oxygen deprivation
  • Physical agents
  • Chemical agents
  • Infectious agents
  • Immunological reactions
  • Genetic abnormalities
  • Nutritional imbalances

REVERSIBLE CELL INJURY

  • Characterized by functional and structural changes that can be corrected if the damaging stimulus is removed.

NECROSIS

  • Pathologic process due to severe injury; characterized by denaturation of proteins and membrane damage.
  • Types of necrosis:
    • Coagulative
    • Liquefactive
    • Gangrenous
    • Caseous
    • Fat
    • Fibrinoid

SUMMARY

  • Cell exposure to stress can lead to reversible injury or cell death (necrosis).
  • Reversible injuries include cellular swelling and fatty changes.
  • Necrosis involves membrane destruction and inflammation.
  • Recognized patterns of necrosis vary based on condition and tissue type.