Pathophysiology Overview
Introduction to Pathophysiology
Pathophysiology: Study of functional changes that occur in the body as a result of a disease or disorder.
Key Terminology: Understand important terms and their interrelationships.
Learning Objectives
Familiarize with key terms.
Comprehend the impact of genetic and environmental factors on aging, lifespan, and individual health outcomes.
Understanding Pathophysiology
Patho: Disease or abnormality.
Physiology: Study of normal functions of living organisms.
Important to note: Not every pathology alters physiological function, and vice versa.
Key Definitions
Disorder: Disturbance/abnormality of function indicating incomplete health.
Example: Major Depressive Disorder affects mood control centers in the CNS.
Disease: Specific pathological condition with distinct features.
Example: Chronic Obstructive Pulmonary Disease (COPD) causes impaired gas exchange, resulting in coughing and shortness of breath.
Disease Classification
Acute Disease: Rapid onset and resolution (e.g., sore throat).
Chronic Disease: Gradually develops and persists (e.g., diabetes).
Subacute Disease: Faster onset than chronic, but longer duration than acute.
Clinical Manifestations
Indicators of disease related changes in body structure/function.
Signs: Objective (e.g., ECG changes).
Symptoms: Subjective (e.g., chest pain).
Syndrome: Collection of signs and symptoms occurring together; can arise from various causes.
Disease in Clinical Practice
Signs: Objective measures; examples include blood pressure and weight.
Symptoms: Subjective experiences; examples include pain and nausea.
Aetiology (Cause)
Idiopathic: Unknown cause.
Infectious Agents: Bacterial infections like pneumonia damaging lung tissue.
Genetic Causes: Conditions like Down syndrome linked to chromosome 21 trisomy.
Environmental Factors: Trauma or lifestyle choices, like smoking, increase disease risk.
Important Case Study - Carli
55-year-old female with a significant smoking history presenting with respiratory symptoms.
Diagnosed with small cell lung carcinoma, a major consequence of smoking, which is the leading cause of cancer-related death for women in Australia.
Environmental Factors in Lung Cancer
Smoking and exposure to toxins are major risk factors.
Stress and cellular aging increase disease susceptibility.
Epidemiology of Diseases
Epidemiology: Study of disease causes, distribution, and control in populations.
Identifies high-risk groups and informs healthcare policy and funding.
Incidence vs. Prevalence
Incidence: New cases diagnosed in a given timeframe.
Prevalence: Total number of cases (both new and existing).
Morbidity and Mortality
Morbidity: Percentage of the population affected by a disease.
Mortality: Death rate associated with a specific disease.
Cellular Changes and Aging
Aging leads to functional decline and increased susceptibility to diseases like chronic respiratory infections and coronary artery disease.
Normal vs. Reversible Injury: Mild stress can cause reversible changes. Severe stress may lead to irreversible injuries and cell death.
Cellular Adaptations to Stress
Atrophy: Decrease in cell size due to reasons like disuse or decreased hormones.
Hypertrophy: Increase in cell size from workload (e.g., muscle training).
Hyperplasia: Increase in cell number, often due to hormonal signals.
Metaplasia: Replacement of one cell type with another; often reversible.
Dysplasia: Abnormal cell growth; precancerous.
Apoptosis vs. Necrosis
Apoptosis: Programmed cell death; controlled process eliminating dysfunctional cells.
Failure leads to cancer.
Necrosis: Unregulated cell death resulting from irreversible injury; triggers inflammation.
Summary of Lifespan Changes
General aging leads to reduced functionality in various body systems: blood flow, organ function, and muscle mass decline.
Pathophysiology varies significantly across different age groups and specific diseases manifest differently based on age.