Patofisiologi

• Pathophysiology


  The study of the physical and functional changes that accompany a particular syndrome or disease
• Pathophysiology


  • Concerned with the mechanisms responsible for the initiation, development, and treatment of pathological processes in humans and animals
  • A modern integrative biomedical science founded on basic and clinical research
• Pathophysiology helps medical students and doctors find answers to questions about the cause, development, underlying mechanisms, signs and symptoms of diseases
• Health


  A state of equilibrium, balance, consistency, and stability
• Disease


  A disruption of health, can be communicable or non-communicable
• Factors involved in communicable diseases

  • Host
  • Agent
  • Environment
• Types of diseases


  • Hereditary
  • Congenital
  • Developmental
  • Genetic
  • Inflammatory
  • Degenerative
  • Metabolic
  • Neoplastic
  • Nutritional
  • Immunologic
  • Trauma
  • Infectious
• Examples of general pathophysiology


  • Cough
  • Fever
  • Hyper/Hypothermia
  • Shock
  • Stress
  • Edema
  • Control mechanism disturbance
• Examples of specific pathophysiology

  • Cardiovascular system
  • Respiratory system
  • Neurologic system
  • Gastrointestinal system
  • Musculoskeletal system
  • Endocrine system
  • Renal system
  • Hematologic system
  • Infectious diseases
  • Cancer
• Cardiovascular system pathophysiology


  Relationship between oxygen supply and demand
• Respiratory system pathophysiology


  Abnormalities in the structures of the respiratory system, ventilation and perfusion
• Common respiratory disorders


  • Obstructive lung diseases
  • Restrictive lung disease
  • Pulmonary edema
  • Pulmonary embolism
• Gastrointestinal system pathophysiology


  • Disorders of motility
  • Disorders of secretion
  • Disorders of digestion and absorption
  • Disorders of organ function
• Basics of pathophysiology include the structure of cells, how cells reproduce, age and die, the concept of homeostasis, and the causes and process of disease development
• Scope of pathophysiology


  • Cellular and molecular (growth, adaptation, cellular injury, cell death)
  • Neoplastic development, progression, invasion, spreading
  • Inflammation (inflammatory response, acute and chronic inflammation)
• Pathology provides the scientific foundation for the practice of medicine
• Without Pathology, there is No Medicine
• Pathology


  The study of suffering, the study of diseases
• Etiology and Pathogenesis


  Disease originated at cellular level: arise from disturbances at the molecular level (gene, protein, etc)
• The cell


  • Storage unit (DNA)
  • Transcription (RNA)
  • Translation (Amino Acid)
  • Working Unit (Protein)
• Gene Silencing


  • Long non-coding RNA (lncRNA) can bind to regions of chromatin, restricting RNA polymerase access to coding genes within the region
  • MicroRNA (miRNA) binds to mRNA to repress translation
• Signaling Receptors


  • Tyrosine-Kinase based
  • Nuclear Receptor
  • Seven-Transmembrane Receptor
  • Notch
  • Wnt/Frizzled
• Extracellular Matrix (ECM)


  Network of interstitial proteins that provides mechanical support, controls cell proliferation, scaffolds tissue renewal, and establishes tissue microenvironment
• Cell Cycle


  Sequence of events that results in cell division: G1, S, G2, M
• Cell Cycle Regulation


  • Driven by cyclins and cyclin-dependent kinases (CDKs)
  • Surveillance mechanisms at checkpoints to ensure genetic integrity
• Stem Cells


  Totipotent, pluripotent, and adult stem cells have capacity for self-renewal and differentiation
• Causes of Cell Injury

  • Toxins
  • Hypoxia and Ischemia
  • Infectious Agents
  • Genetic Abnormalities
  • Immunologic Reactions
  • Nutritional Imbalances
  • Physical Agents
  • Aging
• How Disease Develop


  1. Cells interact with environment

  2. Maintain homeostasis through adaptation

  3. Cell injury occurs when adaptive capability is exceeded

  4. Reversible injury can restore homeostasis

  5. Severe/persistent stress results in irreversible injury and cell death
• Cellular Adaptations to Stress

  • Physiologic adaptations in response to normal stimuli
  • Pathologic adaptations in response to stress to avoid injury, but at expense of normal function
• Metaplasia


  Change in which one adult cell type is replaced by another adult cell type, often in response to chronic irritation, to make cells better able to withstand the stress
• Metaplasia


  • May be reversible with removal of stressor
  • Can progress to dysplasia and cancer under persistent stress
• Metaplasia


  • Cells are better able to withstand the stress (usually induced by altered differentiation of pathway of tissue stem cells)
  • May result in reduced functions or increased propensity for malignant transformation
• Barrett esophagus


  • Esophagus is normally lined by nonkeratinizing squamous epithelium (suited to handle friction of a food bolus)
  • Reflux from the stomach causes metaplasia to non-ciliated, mucin-producing columnar cells (better able to handle the stress of acid)
• Metaplasia


  • Reversible, in theory, with removal of the driving stressor
  • Under persistent stress, can progress to dysplasia and eventually result in cancer
• Vitamin A deficiency


  • Can result in metaplasia
  • Vit A→differentiation of specialized epithelial surface (conjunctiva)
  • Deficiency Vit A→metaplasia into stratified keratinizing squamous epithelium→keratomalacia
• Mesenchymal tissue


  • Can also undergo metaplasia
  • Myositis ossificans→connective tissue within muscle changes to bone during healing after trauma
• Hypertrophy


  • Increase in the size of cells resulting in an increase in the size of the organ
  • Involves gene activation, protein synthesis, and production of organelles
  • Can be physiologic or pathologic and is caused either by increased functional demand or by growth factor or hormonal stimulation
• Hypertrophy and hyperplasia generally occur together (e.g. uterus during pregnancy)
• Permanent tissues (e.g., cardiac muscle, skeletal muscle, and nerve) however, cannot make new cells and undergo hypertrophy only
• Cardiac myocytes


  • Undergo hypertrophy, not hyperplasia, in response to systemic hypertension