Introduction to Pathology Lecture Quiz

Introduction to Pathology

• Pathology is the branch of medical science focused on studying the causes, nature, and effects of diseases.
• The term derives from Greek: "Pathos" (disease/suffering) and "Logos" (study).
• Histopathology involves microscopic examination of disease-affected tissues, while pathophysiology focuses on functional changes resulting from diseases or injuries.

Classification of Diseases

• Diseases can be classified as Congenital (present at birth) or Acquired (develops later).
• Acquired diseases can further be categorized into:
  • Inflammatory
  • Vascular
  • Growth disorders
  • Metabolic
  • Degenerative
  • Drug-induced
  • Infective

Key Concepts in Pathology

• General pathology studies basic reactions of cells and tissues, while systemic pathology examines specific organ responses.
• Morphology refers to structural changes in cells or tissues, while etiology denotes the cause of disease.
• Pathogenesis details mechanisms of morphological changes.

Objectives of Pathology

• Diagnose diseases.
• Prevent diseases.
• Facilitate successful therapies.

Signs, Symptoms, and Lesions

• Signs: Objective indications detectable by a physician.
• Symptoms: Subjective feelings or departures from normal function reported by the patient.
• Lesion: Abnormal tissue resulting from disease or trauma.

Prognosis

• Prognosis is a clinician's estimate of the expected outcome and severity of a disease.

Historical Context

• Rudolph Virchow, known as the "Father of Modern Pathology," emphasized observing changes in diseased tissue at a cellular level.

Diagnostic Pathology

• Biopsy: Tissues removed and examined for diagnostic purposes.
  • Types include needle biopsy, endoscopic biopsy, incisional biopsy, and excisional biopsy.
• Cytology: Study of normal and abnormal cell characteristics.
• Autopsy: Examination of a deceased body to ascertain cause and manner of death.

Cellular Response to Stress

• Cells maintain homeostasis but can adapt to challenges through structural and functional changes.
• Adaptations include atrophy, hypertrophy, hyperplasia, and metaplasia.
• Exceeding adaptive limits can lead to cell injury, either reversible or irreversible.

Cellular Adaptations Explained

• Atrophy: Decrease in cell size due to loss of substance, often resulting from decreased workload or ischemia.
• Hypertrophy: Increase in cell size and tissue due to synthesis of more structural components, often seen in muscle cells (e.g., during pregnancy).
• Hyperplasia: Increase in cell number, contributing to tissue growth, can be physiological (normal functions like pregnancy) or pathological (excessive hormonal stimulation).
• Metaplasia: Replacement of one cell type by another, typically to adapt to environmental stressors.

Cellular Adaptation Examples

• Atrophy: Can result from immobilization, ischemia, undernutrition, or loss of endocrine stimulation.
• Hypertrophy: Seen in skeletal muscles of athletes or in organ enlargement due to increased workload.
• Hyperplasia: Notable in the uterus during pregnancy from both hypertrophy and hyperplasia of smooth muscle.

Significance of Cellular Adaptations

• Adaptive responses aim to maintain cell viability amid stress.
• Persisting harmful stimuli may lead to cell injury and ultimately cell death, highlighting the importance of understanding these processes in pathology.