1. The Human Immune System
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2. What is the immune system?
The body’s defense against disease causing organisms, malfunctioning cells, and foreign particles

3. Major Components First line of defense—attempts to keep pathogens out
Second line of defense---attacks pathogens that have invaded

4. The First Line of Defense
Enzymes in mouth
Skin
Mucus
Stomach acid

5. The Second Line of Defense ~White Blood Cells~
white blood cells (WBCs) attack invaders
WBCs normally circulate throughout the blood, but will enter the body’s tissues if invaders are detected
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6. Other Cells of the Immune System
Macrophages: engulf and digest microorganisms and viruses
T-cells: coordinate immune system and attack infected cells
B-Cells: make antibodies (proteins that attach specific antigens)

8. Other responses
Fever: T-cells send chemical signal to turn up temp slows growth of pathogen and increases B and T cells
Memory B Cells: can produce B Cells to make enough antibodies in 3-4 days to protect you instead of 2 weeks

9. Challenges to the Immune System
Allergies: overreaction to antigen
Autoimmune diseases: a disease which attacks the body’s own cells (rheumatoid arthritis, type 1 diabetes, multiple sclerosis and lupus)
Cancer: when cells divide at an uncontrolled rate
AIDS/HIV: destroys helper T-cells

10. Other Systems the Immune System works with
Skeletal– bone marrow produces white blood cells
Circulatory System—transportation
Integumentary system—skin
All systems protected by immune system