Unit VII – Human Health and Disease

📘 UNIT VII – HUMAN HEALTH AND DISEASE

🔹 1. Health

Health = complete physical, mental & social well-being, not just absence of disease.

Factors affecting health: genetic disorders, infections, lifestyle (diet, exercise, habits).

🔹 2. Diseases

A disease = any condition disturbing normal body function.

  • Infectious: Caused by pathogens. (TB, Malaria)
  • Non-infectious: Not caused by pathogens. (Diabetes, Cancer)

🔹 3. Common Diseases

  • Bacterial: Typhoid, Pneumonia
  • Viral: Common cold, Dengue, AIDS
  • Protozoan: Malaria, Amoebiasis
  • Helminthic: Ascariasis, Filariasis

🔹 4. Immunity

Ability of body to resist disease.

  • Innate: Present from birth, non-specific (skin, phagocytes).
  • Acquired: Specific, developed during life:
    • Active: Infection or vaccination (own antibodies).
    • Passive: Ready-made antibodies (anti-venom).

🔹 5. Vaccination & Immunization

Vaccines = antigens → stimulate antibodies + memory cells.

  • BCG → Tuberculosis
  • OPV → Polio
  • Hepatitis-B vaccine → Hepatitis

🔹 6. Allergy

Hypersensitive reaction to allergens (pollen, dust).
Examples: Asthma, rhinitis.

🔹 7. Autoimmune Diseases

Immune system attacks own body cells.
Examples: Rheumatoid arthritis, Type-1 diabetes.

🔹 8. Cancer

Definition: Uncontrolled cell division (loss of regulation).

Causes: Mutations, carcinogens (tobacco, radiation, viruses).

Treatment: Surgery, chemotherapy, radiotherapy, immunotherapy.

🔹 9. Drugs & Alcohol Abuse

Misuse of substances like heroin, cocaine, morphine, alcohol damages nervous system & health.

Example: Alcoholism → Liver cirrhosis.

✅ Conclusion

Human health & disease connects biology with real-life issues: infections, immunity, vaccines, lifestyle disorders. Awareness & prevention help reduce disease burden.

Example: Rabies bite → Immediate rabies vaccine + passive antibody injection = life-saving immunology in action.