Pathology Lecture Notes

Assessment Methods

  • Continuous Assessment Methods

    • Quiz: 20%

    • Lab Report: 10%

    • PBL Report: 5%

    • PBL Presentation: 5%

    • Total for Continuous Assessment: 40%

  • Final Examination Methods

    • OSPE: 10%

    • MEQ: 25%

    • MCQ: 25%

    • Total for Final Examination: 60%

Must Pass Policy

  • Institution: International Islamic University Malaysia (IIUM)

  • Program: Bachelor of Nursing (Honours), Kulliyyah of Nursing

  • Policy Overview:

    • The Kulliyyah of Nursing adopts Option 2 of the University’s Assessment Policy.

    • Students who fail Continuous Assessment (CA) or Final Assessment (FA) (score <50%) may redo/repeat/resit assessments as per policy.

    • CA: Students must redo any failed component before the semester ends.

    • FA: Repeating/resitting follows SAPER procedures.

    • Passing Requirement: Minimum 50% for each component (CA & FA).

  • Example Scenario:

    • Student A, Course A

    • CA: 17/40 → Must redo to achieve 20/40 (min 50%) to be eligible for FA.

    • If the student fails the CA after redo, they are not eligible to sit for the FA.

    • CA: 25/40 & FA: 25/60 → Overall fail → student must repeat/resit according to policy or SAPER procedures.

  • Note: This does not apply to the Final Professional Examination; effective from Semester 1, 2025/2026.

Introduction to Pathology

  • Overview:

    • Pathology is a discipline that investigates the causes (etiology) of disease and the underlying mechanisms (pathogenesis) that lead to the observable signs and symptoms in patients.

  • Definitions:

    • Pathology: Translates to "study (logos) of suffering (pathos)."

Etiology vs Pathogenesis

  • Etiology:

    • Refers to the origin of a disease, including underlying causes and modifying factors.

    • Example Diseases: Hypertension, Diabetes, Cancer - often caused by a combination of genetic susceptibility and environmental triggers.

  • Pathogenesis:

    • Refers to the series of steps in the development of disease, which includes how etiologic factors induce cellular and molecular changes, leading to structural and functional abnormalities.

    • Note: Understanding both is crucial for rational treatment development.

What is Disease?

  • Definition: Disease is an expression of discomfort due to structural or functional abnormality.

  • Key Considerations:

    • Etiology: What causes the disease (e.g., bacteria, viruses, heat, radiation, genetics)?

    • Pathogenesis: Steps involved in the disease development.

    • Morphology: Structural changes in cells or tissues.

    • Functional Consequences: Effects of the abnormalities.

Overview of Cellular Responses

  • Cellular State:

    • Normal Cell (Homeostasis) ⟶ Stress ⟶ Injurious Stimulus ⟶ Adaptation or Cell Injury (Reversible or Irreversible) ⟶ Cell Death (Necrosis or Apoptosis).

    • Cells generally maintain homeostasis but can adapt to physiologic stresses.

    • If homeostasis cannot be maintained, cells may suffer injury leading to necrosis (irreversible injury) or apoptosis (programmed cell death).

Cellular Adaptations

  • Definition: Cellular adaptations are reversible changes in cell size, phenotype, metabolic activity, or function in response to environmental changes.

    • Types of Adaptation:

    • Physiologic Adaptations: Responses to normal stimulation (e.g., hormonal growth during pregnancy).

    • Pathologic Adaptations: Responses to stress allowing cells to modulate their structure and function to avoid injury (e.g., thickening of heart muscle under pressure).

Types of Cellular Adaptation

  1. Hypertrophy:

    • Definition: Increase in cell size leading to increase in organ size; occurs without an increase in cell number.

    • Causes: Increased functional demand, growth factor, or hormonal stimulation.

    • Examples:

      • Physiologic hypertrophy: Uterine enlargement during pregnancy, weightlifting-induced muscle growth.

      • Pathologic hypertrophy: Cardiac enlargement due to hypertension.

  2. Hyperplasia:

    • Definition: Increase in tissue mass through cell replication; can occur with hypertrophy.

    • Requires cell populations capable of division.

    • Examples:

      • Physiologic hyperplasia: Breast tissue proliferation at puberty.

      • Pathologic hyperplasia: Excessive hormonal stimulation leading to endometrial hyperplasia after menstrual cycles.

  3. Atrophy:

    • Definition: Shrinkage of cell size due to loss of substance; affected tissue or organ diminishes in size.

    • Causes include decreased workload, diminished blood supply, inadequate nutrition, loss of endocrine stimulation, and aging.

    • Mechanisms involve decreased protein synthesis and increased degradation, commonly through autophagy.

  4. Metaplasia:

    • Definition: Reversible change where one adult cell type is replaced by another type better suited to survive environmental stress.

    • Common example: Respiratory epithelium of smokers, where ciliated cells are replaced by stratified squamous cells for durability but lose some protective functions.

  5. Dysplasia:

    • Definition: Enlargement of an organ or tissue by proliferation of abnormal cells; could be an early stage of cancer.

Conclusion

  • Cellular adaptations promote tissue survival under stress but may lead to dysfunction or disease if the underlying issues are not resolved. Understanding these processes is essential in pathology to inform treatment and preventive measures.