Immunity

basic for students

1. IMMUNITY

2. OBJECTIVES Definition Classification Innate Immunity: Factors and types Acquired Immunity: Types Difference Measurement Local Immunity Herd Immunity

3. DEFINITION Immunity refers to the resistance exhibited by the host towards injury caused by microorganisms and their products (toxin).

4. CLASSIFICATION INNATE IMMUNITY (Present Since Birth ) AQUIRED IMMUNITY ( After Birth Specific immunity to a Particular Pathogens ) ACTIVE IMMUNITY PASSIVE IMMUNITY NATURAL ARTIFICIAL NATURAL ARTIFICIAL

5. INNATE IMMUNITY Innate immunity is the resistance to infections which an individual possesses by virtue of his genetic or constitutional make up. Species Immunity Racial Immunity Individual Immunity

6. FACTORS INFLUENCING THE LEVEL OF IMMUNITY Age Hormonal Influences Nutrition

7. Age

8. Hypothyroidism

9. Malnutrition

10. Mechanisms of innate immunity Mechanical Barriers and Surface Secretions Skin Mouth or Oral Cavity Gastrointestinal Tract Upper Respiratory Tract Genitourinary Tract Conjunctiva Antibacterial Substances in Blood and Tissues Cellular Factors : Phagocytosis, Macrophages Inflammation Fever Acute Phase Proteins

11. Acquired Immunity “Resistance acquired by an individual during life” 1. Active immunity 2. Passive immunity

12. AQUIRED IMMUNITY ( After Birth Specific immunity to a Particular Pathogens ) ACTIVE IMMUNITY PASSIVE IMMUNITY NATURAL ARTIFICIAL NATURAL ARTIFICIAL

13. Comparison of active and passive immunity ACTIVE IMMUNITY PASSIVE IMMUNITY Produced actively by host’s immune system Received passively. Induced by infection or by immunogens Readymade antibody transferred Durable effective protection Transient, less effective Immunity effective only after lag period Immediate immunity Immunological memory present No memory Not applicable in the immunodeficient Applicable in immunodeficient

14. MEASUREMENT OF IMMUNITY Demonstration of the Specific Antibody In Vitro or In Vivo Methods

15. LOCAL IMMUNITY: It is conferred by secretory immunoglobulin A ( secretory IgA ) produced locally by plasma cells present on mucosal surfaces or in secretory glands. poliomyelitis immunization , influenza immunization etc.

16. HERD IMMUNITY: Herd immunity is the level of resistance of a community or a group of people to a particular disease. Low and high level