1. 9th BIOLOGY
The Immune System

2. Non-specific Immunity
Born with some immunity
Helps prevent disease
Helps slow disease progression
First line of defense

3. Non-specific, cont. Physical Barrier- unbroken skin
Skin oil acidic, inhibits pathogens
Chemical barrier- saliva, tears, nasal secretions
All contain lysozyme
Mucus- sticky
Cilia- sweep irritants away
HCl in stomach, pH of 2

4. Non-Specific Response
Cellular defense- WBCs
Neutrophils, macrophages are phagocytic
Engulf and destroy antigen
Complement proteins- enhance phagocytic response
Interferon-secreted by virally infected cells
Binds to cells, produces antiviral proteins to prevent viral replication

7. Non-Specific Response, cont.
Inflammatory response-
Pathogens damage tissuechemicals released attract phagocytosis
Increase capillary permeability to increase blood flow to the area
Result is more WBCs to the rescue

9. Specific Immunity Lymphatic System- Lymphatic Organs-
Includes organs and cell that filter lymph
Lymph is tissue fluid that bathes body cells
Lymphatic Organs-
Contain lymphatic tissue, lymphocytes, connective tissue
Lymphocytes- WBC produced in red bone marrow
Include: lymph nodes, tonsils, spleen, thymus

11. Lymphatic Organs
Lymph nodes- filter lymph and remove foreign particles
Tonsils and adenoids- form a protective ring around nasal and oral cavities
Spleen- stores blood and destroys damaged RBCs
Thymus- above the heart, T cell maturation

13. B Cells B lymphocytes- Mature in bone marrow React with antigen
Antibody factories- memory for antigen, quicker immune response upon next exposure.
Antibody stimulation caused by vaccination or direct exposure to antigen

14. T Cells Mature in thymus First responder cell
Activation of T cells required to continue cascade of events
Macrophage activation-
Macrophage engulfs antigen and displays pieces of it on surface
T cells bind to presented antigen activates immune system, including B cells

15. T Cell Response
Cytotoxic T cells- destroy pathogens and release cytokines
Cytokines stimulate other immune cells to react

17. Passive and Active Immunity
Passive- acquire antibodies from somewhere else
Infants acquire some antibodies from their mothers to protect them until their immune system matures
Receiving injections of antibodies from other humans or animals
Anti-venom
Hep A
Rabies
Tetanus

18. Passive and Active, cont.
Active- you make the antibodies yourself
Vaccination- series
1st shot- primary response
Booster shot- secondary response- quicker and more intense
Having disease
Chickenpox

19. Immune System Failure HIV/AIDS- targets CD-4+ receptor on T cells
Shuts down immune response by deactivating T cells
Mild, flu-like symptoms upon first exposure
Tests for HIV check for presence (HIV+) or absence(HIV-) of antibody to HIV