Mechanisms of Disease Study Notes

Learning Objectives

  • Understand disease terminology and patterns.

  • Describe basic disease mechanisms and risk factors.

  • Categorize pathogenic organisms and their disease mechanisms.

Studying Disease

  • Health: Physical, mental, and social well-being.

  • Disease: Abnormality threatening health.

  • Etiology: Study of disease causation.

  • Disease types: Acute (sudden) and chronic (long-lasting).

Disease Terminology

  • Communicable disease: Transmitted between individuals.

  • Idiopathic disease: Unknown cause.

  • Incubation: Latent infection stage.

  • Remission: Temporary recovery from symptoms.

  • Pathogenesis: Development pattern of disease.

Signs and Symptoms

  • Signs: Objective abnormalities (e.g., temperature).

  • Symptoms: Subjective experiences (e.g., pain).

Patterns of Disease

  • Epidemiology: Study of disease occurrence and transmission.

  • Endemic: Native to a region.

  • Epidemic: Widespread in a community.

  • Pandemic: Global spread of disease.

Mechanisms of Disease

  • Pathophysiology: Physiological aspects of disease.

  • Genetic: Altered genes cause protein abnormalities.

  • Infectious: Pathogens damage the body.

  • Neoplastic: Abnormal tissue growth (tumors/cancer).

  • Traumatic: Damage from physical/chemical agents.

  • Metabolic: Endocrine imbalances, malnutrition.

  • Inflammatory: Immune response; may lead to autoimmunity.

Risk Factors for Disease

  • Genetics, age, lifestyle, stress, environment, preexisting conditions.

Pathogenic Organisms

  • Viruses: Intracellular parasites, not technically living.

    • Types: DNA viruses (e.g., HPV) and RNA viruses (e.g., Influenza).

  • Prions: Abnormal proteins causing degenerative diseases.

  • Bacteria: Tiny cells, can be aerobic/anaerobic or gram-positive/negative.

  • Fungi: Yeasts and molds, often resistant to treatment.

  • Protozoa: Large single-celled organisms, can infest cells.

  • Pathogenic Animals: Nematodes, platyhelminths, and arthropods cause harm.

Prevention and Control of Pathogens

  • Transmission: Person-to-person, environmental, opportunistic, vector.

  • Preventive Measures: Education, sanitation, vector population control.

  • Treatment Strategies: Vaccination, drug therapy, antibiotics, antiviral drugs.

Tumors and Cancer

  • Neoplasms: Abnormal cell growth; benign (localized) vs. malignant (spread).

  • Metastasis: Spread of cancer cells to new locations.

  • Causes of Cancer: Genetic factors, carcinogens, age, environmental factors, viruses.

  • Signs of Cancer: Non-healing sores, unusual bleeding, lumps, persistent cough.

Inflammation

  • Function: Reduces injury and maintains homeostasis.

  • Signs: Redness, heat, swelling, pain.

  • Types: Acute (immediate, protective) vs. chronic (can damage tissues).