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40-2 The Immune System. Pg. 1036. Introduction. 1. The immune system fights infection by producing cells that inactivate (DEFEAT!) foreign substances/cells. A. Nonspecific Defenses. 1. Nonspecific defenses do not discriminate. A. Nonspecific Defenses.
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40-2 The Immune System Pg. 1036
Introduction • 1. The immune system fights infection by producing cells that inactivate (DEFEAT!) foreign substances/cells.
A. Nonspecific Defenses • 1. Nonspecific defenses do not discriminate.
A. Nonspecific Defenses • 2. Skin is the first line of defense and most important nonspecific defense.
A. Nonspecific Defenses • 3. The 2nd line of defense is an inflammatory response which occurs in response to injury/infection.
A. Nonspecific Defenses • 4. Another 2nd line of defense is a fever when the body tries to kill pathogens/fight infection.
B. Specific Defenses • 1. Immune responses attack specific substances called antigens (viruses, bacteria, etc.)
B. Specific Defenses • 2. Two types of cells recognize specific antigens: • B Lymphocytes (B Cells) • T Lymphocytes (T Cells)
B. Specific Defenses • 3. B cells provide immunity through body fluids; this process is called humoral immunity.
B. Specific Defenses • 4. T cells provide immunity to against pathogens INSIDE the cell; this process is called cell mediated immunity.
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.
B. Specific Defenses • 6. When antigens enter the body, plasma cells release antibodies. • 7. Antibodies are proteins that recognize/bind to antigens.
Think about it? • Why would it be difficult to accept an organ transplant???
C. Acquired Immunity • 1. Vaccinations are a form of acquired immunity where an individual receives a weakened form of the pathogen to produce immunity.
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.