1. 40-2 The Immune System Pg. 1036

2. Introduction 1. The immune system fights infection by producing cells that inactivate (DEFEAT!) foreign substances/cells.

3. A. Nonspecific Defenses 1. Nonspecific defenses do not discriminate.

4. A. Nonspecific Defenses 2. Skin is the first line of defense and most important nonspecific defense.

5. A. Nonspecific Defenses 3. The 2 nd line of defense is an inflammatory response which occurs in response to injury/infection.

6. A. Nonspecific Defenses 4. Another 2 nd line of defense is a fever when the body tries to kill pathogens/fight infection.

7. B. Specific Defenses 1. Immune responses attack specific substances called antigens (viruses, bacteria, etc.)

8. B. Specific Defenses 2. Two types of cells recognize specific antigens: – B Lymphocytes (B Cells) – T Lymphocytes (T Cells)

9. B. Specific Defenses 3. B cells provide immunity through body fluids; this process is called humoral immunity.

10. B. Specific Defenses 4. T cells provide immunity to against pathogens INSIDE the cell; this process is called cell mediated immunity.

11. B. Specific Defenses 5. T cells can become – Killer T cells that track down/destroy antigens – Helper T cells that make Memory T cells – Memory T cells that respond if the same antigen enters the body again.

12. B. Specific Defenses 6. When antigens enter the body, plasma cells release antibodies. 7. Antibodies are proteins that recognize/bind to antigens.

13. Think about it? Why would it be difficult to accept an organ transplant???

14. C. Acquired Immunity 1. Vaccinations are a form of acquired immunity where an individual receives a weakened form of the pathogen to produce immunity.

15. C. Acquired Immunity 2. Active immunity is the body's response to a vaccine by making antibodies. 3. Passive immunity is when antibodies are injected into the bloodstream.