Microbiology Unit 4 – Flashcards
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substance capable of initiating an immune response; usually PART of a protein (8-16 aa's long) |
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antigen |
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study of mechanisms that protect an individual from injury; ability of body to recognize what is ATYPICAL |
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immunology |
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injuries to body from bacteria, parasites, viruses, fungi |
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exogenous microorgs |
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WBCs that are 1st responders, phagocytic, not great at triggering immune response |
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neutrophils |
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WBC that produce histamines |
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basophils |
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mature into macrophages |
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monocytes |
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lymphocytes are involved in ___ immunity (specific or innate) |
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specific |
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no memory, triggered every time org comes in |
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innate immunity, non-specific immunity |
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3 parts of nonspecific immunity (2 lines of defense) |
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surface barriers - 1st line cellular defenses - 2nd line chemical defenses - 2nd line |
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first line of defense in innate immunity |
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skin and mucous membrane normal flora |
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how does sebum contribute to 1st line of innate immunity? |
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antimicrobial properties, make skin slightly acidic |
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examples of mucous membranes that contribute to nonspecific immunity |
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low pH in vagina, acids in stomach, lysozomes in tears |
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what cells in 2nd line of innate immunity trigger specific/adaptive immunity system the mostwhere are they foundhow do they work |
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dendritic; tissues; migrate out looking for T and B cells to ignite adaptive immunity |
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can attack any cell, but not phagocytic, they attack cell membrane and release cytolytic chemicals - type of T cell in innate immunity system |
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Natural Killer cells |
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steps of phagocytosis (4) |
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chemotaxis attachment ingestion digestion |
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3 chemical defenses (2nd line of defense in innate immunity) |
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inflammation fever complement system |
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stimulates WBCs reduces available free plasma iron induces Interleukin-1 slows growth rate of certain pathogens 1st response to be recognized |
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Fever |
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responds to foreign invaders, BUT ALSO physical trauma infection by microorgs chemical irritation burns |
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inflammation |
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fx of inflammatory response |
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localize foreign substances at site of entry, prevent penetration to other tissues, help rebuild damaged tissue to normal |
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heat redness swelling pain loss of fx (may or may not) |
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cardinal signs of local inflammation |
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Prostaglandins dilate vessels (brings Ab and phagoc to site) Forms fibrous connective tissue around site (wall off invaders, prevents spread) clean up debris |
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steps of inflammation |
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collection of cells and fluid in injured area |
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exudate |
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thick yellow exudates containing large #s of PMNs (polymorphoneutrophils) |
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Purulent (suppurative) exudate |
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thin, watery exudates, more plasma than cells (blister) |
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serous exudate |
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microorgs that cause a purulent exudate response (pus formation) -Strep A is this |
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pyogenic |
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causes cascading sequence that results in cell lysis, chemotaxis and or opsorization - 2 pathways (classical and alternative) that involve about 30 proteins |
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complement system |
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involving coding of bacterial cells - adds sticky proteins to cell surface so that it attaches more easily to phagocytizing cells |
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opsonization |
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makes memory, occurs when 2nd line of defense is insufficient for protection (or 2nd line stimulated so long, it activates this) 3rd LINE OF DEFENSE |
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acquired/specific immunity |
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phagocytic cells in 2nd line of defense include |
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neutrophils macrophages dendritic cells |
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MHC class 1 is present in all cells except ___; MHC 1 involved in what? |
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RBC's; Cell-mediated immunity |
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MHC type 2 are in ____ cells; involved in which type of specific immunity? |
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Phagocytic cells; Humoral immunity |
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Humoral immunity involves ____ organism; found in blood and extracellular spaces around cells |
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Extracellular |
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cell-mediated immunity involves ____ cellular pathogens |
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intra |
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we have more extracellular pathogens than intracellular...T or F |
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True |
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Cytotoxic T cells (CD8 cells) are part of ____ immunity; what is their action? |
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cell-mediated; they lyse infected cells |
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B cells, helper T cells (CD4 cells) are involved in ___ immunity |
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humoral |
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what do helper T-1 cells doWhat do helper T-2 cells do? |
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T-1s activate the macrophages; T-2s activate B cells to produce IgM and IgE |
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B cells break down into (2) things |
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Plasma cells and memory cells |
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Antibodies come from?? which immunity involved with? |
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Plasma cells, that come from B cells involved in humoral immunity |
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fx of IgM; fx of IgG |
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1st Ab 1st time infected; 1st Ab 2nd time infected, can cross placenta |
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Fx of IgA Fx of IgD Fx of IgE |
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in tears and saliva; unknown; involved in allergic reactions and fights parasitic worms |
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3rd line of immune defense |
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Specific Immunity |
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immunity whose response is unique to the challenge it's presented, diverse |
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specific immunity |
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activate other cells involved in humoral immunity (macrophages and B cells) and helps produce Ab (CD4 cells) |
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helper T cells |
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Cytotoxic T cells (CD8) cells destroy |
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target cells on contact |
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how many MHC 1 genes do we inherit? MHC 2? What's different about MHC 2 inherited genes? |
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6; 8 MHC 2 genes- 2 chains can recombine to produce many different variants for those 8 genes |
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which type immunity guards from TB, fungi, leprosy, other infections, intracellular viruses and cancer, some kinds of tumors |
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cell-mediated |
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act as chemical messengers in the immune system; called lymphokine when lymphocyte produces it |
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cytokine |
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cytokine that attracts WBCs to infected areas |
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chemokines |
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cytokine that protects against viral infections (shuts downs replication in neighboring cells) |
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interferons |
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cytokine involved in further stimulating the immune response (IL1 - B cell matur and prolif, inflammation; IL2- T cell matur and differentiation |
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interleukins |
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cytokine that's important in inflammatory reaction, it's cytotoxic to cancer cells |
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Tumor Necrosing Factors (TNF) |
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cytokine that is macrophage colony stimulating factor AND stimulats hemopoiesis |
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granulocyte |
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proteosomes fx; involved in what type immunity |
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chew up organism, breaks it down so MHC 1 can pick it up CELL-mediated immunity |
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branch of immunity that protects us against more toxins, bacteria and viruses, deals with extracellular pathogens |
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humoral |
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involves B lymphocytes and plasma cells that produce specific Abs to react with particular pathogen |
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humoral immunity |
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immunoglobulins are also called |
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antibodies; proteins called globulins |
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antibodies held together in Y shape by ___ bonds |
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2 disulfide bonds- very strong |
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what Ab occurs when Ag is introduced to host for 1st time? |
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1st Ab production-- IgM |
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what occurs during lag or latent phase of Ab production? how long last? |
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5-7 days; no detectable Ab now |
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what happens during Log phase of Ab production? How long last? |
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gradual rise in titer (IgM), takes 1-2 weeks |
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what happens during Plateau phase of Ab production? How long last? |
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Ab titer stabilizes, peaking around 3-6 weeks |
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what happens during Decline phase of Ab production? How long last? |
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Ab titer decr due to catabolism of Ab, removal due to formation of immune complexes, halt production of more Ab; takes couple of months (whole process) |
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anamnestic response is what? when does it occur? |
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MEMORY RESPONSE occurs when another exposure to same Ag (days, wks, mos, yrs later) occurs |
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2d Ab production response different how? |
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latent/lag phase shorter (just activ memory, not creating it) IgG is 1st Ab on scene titer response typically 10x greater duration lasts longer, maybe for lifetime, IgG creates stronger memory |
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comprises about 80% all Ab in normal human serum, four subtypes |
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IgG |
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diffuses into extracellular space more easily (smaller), only Ab to neutralize toxin, good at complement cascade |
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IgG |
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IgG3 is the best |
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complement activator |
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IgG1 and IgG3 are better at crossing |
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placenta |
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pentamer, can't cross placenta, BEST complement activator bc it has 10 Ag binding sites |
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IgM |
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antibody in tears and saliva, also vaginal secretions, resp and intest mucus and colustrum |
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IgA |
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Immune Regulation and Antigen Clearance: inhibits IgG complement activation but activates alternative pathway, and prevents bacteria from attaching to mucosal surfaces preventing colonization |
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IgA |
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antibody with unknown fx, may contrib to B cell differentiation *highly susceptible to proteolytic enzymes |
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IgD |
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mediates type 1 hypersensitivity (allergies) and immunity against worms |
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IgE |
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antibody that bonds strongly to mast cells and basophils, releasing histamines and heparin |
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IgE |
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MHC class 2 - how does it work in cell? |
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microbe phagocytized, lysosome breaks it down, MHC class 2 protein comes to lysosome, binds with fave fragment and displays on cell surface |
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which cells involved in humoral immunity? |
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B cells and some helper T cells (if T cells involved, better memory response) |
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which cells involved in humoral immunity? |
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B cells and some helper T cells (if T cells involved, better memory response) |
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once B cell activated in humoral immunity, what happens? |
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produces memory cells and plasma cells (plasma produces antibodies), antibodies attach to Ag, make it easier for Ag to be phagocytized |
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Do both humoral and cell-mediated make memory? |
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YES! |
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Product of humoral immunityproduct of cell-mediated immunity? |
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Ab; cytokines |
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immunity that protects from extracellular pathogens, circ viruses, bact, toxins |
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humoral immunity |
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immunity that protects from intracellular pathogens |
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cell-mediated |
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which type of acquired immunity provides fetal protection? how? |
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humoral...thru IgG Ab |
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Dx test for humoral, for cell-mediated immunity? |
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Ab titer Skin test |
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what is mode of action for humoral immunity? for cell-mediated? |
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Ag-Ab complexes cell-cell contact |
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once acquired immunity activated, ___ are also activated, in differing degrees |
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cell-mediated and humoral immunity |
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MHC class 2 is only in what cellsMHC class 1 found in? |
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phagocytes; all nucleated cells |
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occurs when immune defenses go haywire - could be immediate or delayed *instead of protecting, immune response irritates |
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hypersensitivity |
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immediate hypersensitivity occurs within |
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few min to 24 hours |
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includes classic allergic responses, anaphylactic reactions, involve IgE Ab |
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Type 1 hypersensitivity reactions |
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over 1/2 population allergic to something - T or F |
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TRUE |
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most common observed type of hypersensitivity |
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type 1 - allergic reaction |
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what determines type and severity of allergic reaction |
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nature of Ag amt time Ag entering body route of entry length time betw exposures person's ability to prod IgE Ab site of IgE attachment |
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anaphylaxis that involves mast cell degranulation, ex include hay fever, hives, asthma *symptoms depend on how allergen enters body and sites of IgE attachment |
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localized anaphylaxis |
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immediate allergic reaction, involves basophil degranulation, shock reaction usually occurs within 20 min after exposure ex include: bee stings, penicillin, nut and shellfish allergies, lots of meds |
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systemic anaphylaxis |
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symptoms are: flushed skin with itching, headache, facial swelling, diff breathing, falling BP, nausea, vomiting, abdomin cramps, urination;;;;; possible acute resp distress unconsciousness death |
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systemic anaphylaxis |
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tx for systemic anaphylaxis? how effective is it? |
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adrenaline, Epi, antihistamine - usually works! |
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tx for systemic anaphylaxis? how effective is it? |
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adrenaline, Epi, antihistamine - usually works! |
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cytotoxic reactions seen in bl transfusions, Rh incompatib reactions -- involves IgG and IgM Ab |
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Type 2 hypersensitivity |
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immune complex reactions that occur in serum sickness and certain autoimmune diseases; also certain complications of untreated or inadeq tx of strep throat or other S pyogenes infections ex: lupus, rheumatoid arthritis |
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Type 3 hypersensitivity |
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Delayed (Type 4) hypersensitivity reactions usually seen after ___; part of which immunity? |
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24 hours; cell-mediated immunity |
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Type 4 hypersensitivity reactions occur in what scenarios? |
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transplant rejection, contact dermatitis, tuberculin and fungal skin tests |
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Type 4 hypersensitivity reactions occur in what scenarios? |
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transplant rejection, contact dermatitis, tuberculin and fungal skin tests |
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disease that results when person's IS attacks itself, no longer recog self and non-self; can occur during fetal dev if certain tissues aren't exposed to immune system |
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autoimmune disease |
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IS not fx properly is called ___; also termed ___ |
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immune deficiency, immunosuppressed, etc |
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malnutrition is number one cause of what worldwide? |
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immune deficiency |
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what tx may help someone with certain immune deficiency diseases? |
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bone marrow transplant or gene therapy |
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acquired immunity can be obtained 3 ways |
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active, passive, adopted |
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type of immunity where host is immunocompetent, their own cells can meet challenge, takes wks to dev this, but usually offers lifelong immunity *may be naturally or artificially acquired |
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active immunity |
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getting a vaccine would be _____ immunity |
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active artificial immunity |
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naturally getting rubella virus called ____ immunity |
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active natural immunity |
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type of immunity where 'pre-formed' Ab are given to the host, *offers immediate, short-term protection |
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passive immunity |
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breastmilk, placenta, Hep B Ig are examples of ___ immunity |
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passive |
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bone marrow transplant is ___ immunity (host is immunocompetent, so i.c. transplanted into host) |
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adopted immunity |
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way of creating memory without becoming ill...suspension of orgs or fractions of orgs that stimulate specific immune response so if encountered again, an amanestic response occurs to fight Ag/disease |
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vaccine |
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procedure common in 18th century where dried scabs of smallpox were injected into another person's veins, Pasteur called it vaccination |
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variolation |
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goal of vaccination: herd immunity, also determined as |
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control spread of hard-to-treat-or-prevent (mostly viral) disease |
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vaccine that provides better protection bc it closely mimics disease, considered less safe EX: Sabin (oral) polio, MMR |
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attenuated, live |
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influenza, Salk polio - vaccines that have killed or inactivated orgs in them, no risk |
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inactivated |
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vaccine with inactivated toxins that stimulate immune response to make IgG Ab against toxin TETANUS and DIPHTHERIA |
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Toxoid vaccine |
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vaccine that contains antigenic fragments |
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subunit |
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subunit vaccine in which different microbe produces Ag fragment ex: Hep B - yeast produces part of HBV that stimulates immune response |
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Recombinant vaccine |
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vaccine developed bc children <15 mos don't produce adeq immune response (T-cell mediated) to capsular polysaccharides so proteins are added which stimulate humoral immunity EX are: Hib (Haemophilus influenzae) |
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conjugated vaccine |
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ideal, not approved: naked DNA injected via gene gun which results in protein production of what DNA codes for, proteins stimulate immune response |
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Nucleic acid (DNA or RNA) vaccine |
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IgA inhibits ___ and prevents ____ by preventing bact from attaching to mucosal surfaces |
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IgG; colonization |
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two types of IgA - serum and secretory |
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trace Ig is also called (involved in allergic reactions) |
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IgE |
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injury that comes from malignant or senescent (dying) cells |
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endogenous cells |
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injury from exogenous chemicals - chem include |
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pollens pet dander poison ivy |
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which Ab only one to neutralize toxins? |
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IgG |
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chemicals added to vaccine to improve antigenicity (in US, aluminum salts used) not a vaccine by itself |
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adjuvants |
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Ideal vaccine - describe 4 things |
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taken orally rather than injected (eliminates invasive procedure) gives life-long immunity in single dose stable without refrigeration affordable |
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poison produced by bacteria - def and give examples |
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TOXIN diptheria toxin, botulism toxin, tetanus toxin |
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Anti-toxin (Ab to dipth, tetanus or botulism) |
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Ab produced by host to neutralize bacterial toxin. can be produced actively after exposure or passively thru injection |
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type of vaccine where part of toxin is injected into host to invoke humoral immune response |
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Diptheria and tetanus vaccine TOXOID VACCINE |
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direct tests detect ____ from patient sample |
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antigens |
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indirect tests detect Ab from patients ___ |
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serum |
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study of Ab in serum |
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serology |
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why do we msre Ab? |
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Dx infections and autoimmune diseases |
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serologic testing - if you find only IgM Ab - what does this indicate? |
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recent infection |
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serologic testing - if you find IgM and IgG Ab - what does this indicate? |
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recent infection |
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serologic testing - if you find only IgG Ab - what does this indicate? |
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indicates past infection or past vaccination |
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if IgM is present in newborns, what does this indicate |
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indicates recent dev, IgM first Ab produced in fetal dev |
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if IgG is present in newborns what does this indicate |
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maternal protection - IgG passes thru placenta and colostrum |
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agglutination of RBCs |
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hemagglutination |
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agglutination as a serological test finds |
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particulate Ags |
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RBCs are an indicator for what serological test |
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complement fixation |
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serological test that inactivates toxin or virus |
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neutralization |
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perioxidase enzyme is indicator for which serological test |
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ELISA |
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soluble Ags used for this serological test |
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precipitation |
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Ab linked to fluorescent dye - which serological test? |
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fluorescent Ab technique |
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immunologic test where Ab detected in serum by visualizing Ag-Ab complex |
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Titer |
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immunologic test where Ab detected in serum by visualizing Ag-Ab complex |
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Titer |
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Ab titer |
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Amt of Ab in titer |
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Rapid Group A Strep test, Influenza A and B test, Rotavirus test - examples of Rapid Ag tests |
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ELISA |
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immunologic test in which Ag are injected under epidermal layer of skin and host examined for hypersensitivity reaction |
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Skin test |
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allergy tests and PPD for TB are these types of immunological tests |
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Skin test |
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TB skin test can tell difference betw vaccination and actual exposure - T or F |
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FALSE |
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Principle behind TB skin test |
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prev exposure stimulates cell-med immunity (bc org inside macrophages), in subsequent exposure (skin test), delayed hypersensitivity should respond |
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Principle behind TB skin test |
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prev exposure stimulates cell-med immunity (bc org inside macrophages), in subsequent exposure (skin test), delayed hypersensitivity should respond |
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signs of pos Mantoux test |
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hardening, reddening around area |
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signs of pos Mantoux test |
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hardening, reddening around area |
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any lab test that uses immunologic principles (humoral or cell-mediated immunity) |
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immunologic test |
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acute and convalescent titers should be how far apart |
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four-fold increase in titer, so 4 to 32 |