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Lymphatic System & Immunity Mrs. Donohue
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1. What is the lymphatic system? A. Consists of lymphatic vessels and nodes B. runs beside our circulatory system C. lymphoid organs
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Lymphoid organs 1. Tonsils - protect against invasion of particles that are ingested or inhaled 2. spleen- blood reservoir phagocytes filter foreign materials and old red cells there 3. thymus – changed lymphocytes into T cells (help fight viruses)
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2. How does it help our body? A. Helps to maintain fluid balance in tissues B. absorb digested fats and vitamins from GI C. part of body’s defense against disease (lymphocytes)- WBC’s
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3. What is immunity? A. Preventing disease thru production of antibodies and other plans of attack B. Also to recognize its own tissues and not attack itself – immunological tolerance
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4. What is a pathogen? Disease causing agent Anything that enters the body that is not related to the body Examples: A. such as the bacterium Yersinia pestis, which may have caused the Black PlagueYersinia pestis Black Plague B. Viruses C. Splinter
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5. Types of immunity: A. non-specific (innate) defense mechanisms 1. inherited as part of each organism to attack pathogens 2. epithelial membranes 3. acidity of gastric juices
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5. Types of immunity: B. specific (aquired) immune response 1. can aquire ability to defend against pathogens by prior exposure to those pathogens 2. make antibodies
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6. Non-specific Defense (resistance): 1st line of defense 1. skin 2. mucus and cilia that line nasal cavities and throat 3. gastric (stomach) juice- acidic pH 4. saliva 5. tears
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B1. 2nd line of defense (resistance) inflammation response 1. Phagocytic cells-leukocytes-white cells neutrophils, monocytes & macrophages A.attack pathogens B.release histamine that stimulates blood flow-vasodilates-result is swelling and reddening of infection area
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Inflammation Response
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B2. 2nd line of defense (resistance) inflammation response A. Cells being attacked (T cells) produce interferon B. a protein that prevents viruses (and some cancers) from replicating C. slows down viral infections and allows immune system to function
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B3. 2nd line of defense (resistance) inflammation response A. Complement System B. Makes plasma proteins
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B4. 2nd line of defense (resistance) inflammation response A. Fever B. bacteria secrete endotoxin C. Monocytes (white cells) secrete endogenous pyrogen D. go to brain-get fever-also interferes with bacteria taking in iron
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4A. Purpose of Fevers 1. increases action of white blood cells 2. produces a temperature range in which many pathogens can not live
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7. Specific Defense:3rd line of defense-The Immune System Purpose: to produce antibodies and specialized cells that bind and inactivate pathogens
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A. Antigen - Pathogen (antibody generator) –tells body to make antibodies usually a protein on the surface of a pathogen-ID marker
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B. Sequence of Events for each pathogen 1. recognize pathogen 2. attack 3. destroy 4. remember – memory cells http://vids.myspace.c om/index.cfm?fuseac tion=vids.individual& videoid=22924254http://vids.myspace.c om/index.cfm?fuseac tion=vids.individual& videoid=22924254
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Types of Immunity: 1. Active Immunity Artificial Acquired A. Vaccines-mumps, chicken pox, polio B. Result of prior exposure to an antigen C. Make antibodies D If body comes into contact with the antigen – the antibodies kill it Not get sick
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A. Active Immunity - Primary Response Body produces its own antibodies after vaccine (exposed for 1 st time) 1. Takes 5-10 days to make antibodies 2. May get sick before antibodies are made
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B. Active Immunity - Secondary Response Result is much more rapid and intense 1.Had prior exposure 2. Have antibodies (memory cells) B & T cells 3. make more clones 4. Either never get sick at all or feel sick for one day
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2. Passive Immunity 1. Person receives antibodies from another organism (human) Mom gives natural passive immunity to the fetus for 3 months Breast – feeding – baby gets IgA 2. Snake bite – give antiserum = antibodies (made from horse or sheep that made antibodies when injected with the venom) Neutralizes the venom Person does not develop active immunity
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3.Cellular Immunity (cell-mediated) A. killer T cells release perforin B. directly destroys pathogen C. Antibodies are not made
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4. Humoral (antibody-mediated) immunity Lymphocytes (T & B cells) B cells (plasma cells)—make antibodies
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Normal Immune System T cells directly kill pathogens Helper T cells help the killer T cells kill the pathogen Suppressor T cells turn off the helper and killer T cells after the pathogen is dead
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HIV Vs AID’s HIV - tested positive for the virus AIDS - syndrome caused by HIV - immune system problems appear Usually takes ten years
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HIV-Human Immunodeficiency Virus Virus enters T lymphocytes (killer, helper, & suppressor) Changes the DNA of the lymphs New lymphs kill helper and killer lymphocytes
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HIV-Human Immunodeficiency Virus Pathogen enters the body Not enough killer or helper T cells to kill pathogen Patient becomes septic-septicemia Most deaths from HIV are from infection
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How to treat HIV Decrease viral load=# of HIV cells in body Allows normal # of T cells-can fight infection “Cocktails” “Nukes”-block HIV ability to copy cell’s DNA-can’t make new viral copies Protease inhibitors – prevent infected cells from releasing HIV into body Fusion inhibitor – prevents entry of HIV into the body’s healthy cells
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Why no cure for HIV? Can’t develop vaccine DNA keeps changing
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