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98 Cards in this Set
- Front
- Back
vaccination discovery |
attempt to deliberately induce immunity it was discovered that milkmaids who contracted cowpox was immune to smallpox Jenner inoculated people with cowpox to protect against smallpox |
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immune memory |
recovery from some infectious disease means protection later |
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immune system body's defence system agianst: |
1. pathogens 2. cancers 3. organ transplants |
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immune system functions to: |
1. keep organisms out 2. remove microorganisms that get in 3. combat microorganisms that remain inside 4. fight cancer |
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well- balanced immune should be able to distinguished between |
self and non-self/ pathogens |
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immune system innate/ natural immunity- non specific 1st line |
1. skin 2. mucous membranes and secretions 3. normal flora |
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immune system innate/ natural immunity- non specific 2nd line |
1. innate immune cells 2. inflammation 3. complement 4. antimicrobial substances |
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Immune system adaptive/ acquired immunity- specific responses 3rd line |
specialized lymphocytes 1. B cells- produce antibodies 2.T cells - helper T cells CD4 -killer T cells CD8 |
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skin |
physical barrier between outside and inside environment of our bodies |
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mucous membranes |
thin and permeable barriers |
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mechanical removal |
1. ciliated cells in the respiratory tract- ciliary escalator 2. goblet cells produce mucous 3. mucous/ other secretions flush away microorganisms 4. prevent pathofen binding to host cells |
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secretions: tears, saliva |
ex. lysozyme- break down peptidoglycan |
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secretions: crevicular fluid |
fluid that flows into gingival serum between teeth similar composition to blood serum- the immune cells |
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secretions: gastric juices |
pH1-2 |
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urine/vaginal sevretions |
flushing action, pH balance |
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normal flora compete for... |
space and nutrients |
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normal flora in mouth |
stahplycoccus epidermidis lactobacillus sp. most abundant: alpha streptococci |
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normal flora in skin |
candida albicans most abundant: staphlycoccus epidermmidis |
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normal flora in GI |
escherichia coli lactobacillus sp. most abundant: bacteroides sp. |
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cuts lead to an... |
inflammatory resonse |
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SHARP acronym |
Swelling Heat Altered Function Redness Pain |
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inflammatory response to cuts |
if cut is infected, WBC is increased to mediate the immune response |
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sore throat due to swollen lymph nodes |
LN are where the immune cells multiply in preparation to mount an effective immune response |
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inflammation |
localized tissue response to infection or injury |
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pus |
mixture of dead cells, neutrophils and body fluids |
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abcess |
accumulation of pus- pustules and boils |
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examples of pyogenic or pus producing bcteria |
streptococcus pyogenes stahplycoccus aereus |
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innate immune cells are also called |
WBC or leukocytes |
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WBC part of granulocytes or PMNL- polymorphonuclear leukocytes |
1.neutrophils 2. basophils 3. mast cells 4. eosinophils |
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what do granulocytes or PMNL do? |
direct destruction of pathogens |
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antigen presenting cells? |
1. monocytes 2. macrophages 3. dendritic cells |
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natural killer cells |
destroy infected host cells |
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neutrophils make up how much of total WBC? |
60-70% |
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what can neutrophils do? |
eat cells- phagocytosis have vacuoles containing granules with anti-microbial proteins that function to break down microorganisms and inflammatory mediators |
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neutrophils job |
first to arrive and initiate phagocytosis at the infected site |
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neutrophils life span |
short life span less than one day b/c it doesn't have a mitochondaria |
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what happens when neutrophils die? |
they form nets when they die; a sticky DNA trap for bacteria |
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monocyte/ macrophage make up how much of total EBC |
3-8% |
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monocyte/ macrophage job |
professional phagocyte, very efficient, eats microbes and damaged cells breaks down the infectious pathogen into parts and present "parts" on the cell surface |
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monocyte/ macrophage what are these parts they present |
the parts are antigens, thus monocyte/ macrophage is an antigen presenting cell |
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monocyte/ macrophage in blood circulation, called |
monocyte |
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monocyte/ macrophage in tissue called |
macrophage |
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dendritic cell job |
professional antigen presenting cell; phagocytic important role in activation of adaptive immunity- the specific immune response |
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dendritic cell how does it do its job? |
carries antigen from tissues to the lymph glands where the T and B lymphocytes presents antigen to activate B and t lymphocytes |
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Eosinophil |
major role in defence against parasitic infection |
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eosinophil |
secretes cytolytic enzymes upon contact with pathogens cells circulate in blood until recruited to inflamed tissue |
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basophils |
found in blood similar to function of mast cells release histamine from granules |
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mast cells |
most abundant in submucosal tissues cells surface receptor for immunoglobulin E IgE important role in Type I allergic reactions release histamine once IgE receptor is activates |
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leukocyte granules contain |
chemicals and enzymes to break down pathogens and stimulate other immune cells |
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lytic granules |
contain digestive enzymes ex. lysozyme, to breakdown endocytosed pathogens |
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secretory granules |
1. function to kill pathogens that are too big to eat (parasites) 2. contain chemical messenger substances that attract other immune cells to the site- chemokines 3. also has histamine- an inflammatory mediator |
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natural Killer cells |
lymphocytes without immunological memory |
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natural Killer cells first line of defence against intracellular pathogens |
1. virally infected cells 2. intracellular bacteria/ protozoa 3. cancer cells |
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natural Killer cells how does it destroy cells |
release cytolytic granules that allow for targeted cell destruction |
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natural Killer cells which cells are destroyed? infected cells |
microbial antigen presented in MHC I |
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natural Killer cells which cells are destroyed? virus |
virally infected cells which have lost surface expression of MHC I |
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natural Killer cells which cells are destroyed? cancer cells |
cancer cells that have lost MHC I |
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MHC= major histocompatability complex |
receptor on surface of all normal nucleated cells |
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MHC I and healthy cells |
"self" protein is bound in the MHC I |
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MHC I and sick cells |
virus infected or cancer cells may have a foreign peptide in the MHC I |
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MHC I and immune response |
provides a way for cytotoxic T cells to scan and detect intracellular infection NK cells detect cells that are not showing self-peptides and kill them |
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in humans MHC = |
Human Leukocyte Antigen or HLA, but we just use MHC |
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MHC II |
found only on macrophages, dendritic cells and B lymphocytes all antigen-presenting cells |
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MHC II and the immune response |
bind and present antigen (peptides) to T helper cells in order to initiate adaptive immune response |
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MHC I vs. MHC II found where? |
on all nucleated cells vs. only on apcs |
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MHC I vs. MHC II what does it present? |
presents endogenous vs exogenous peptides |
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MHC I vs. MHC II activates what? |
CD8 cytotoxic cells vs activates CD4 helper cells |
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phagocytosis |
when a cell engulfs a solid particle |
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diapedesis |
the migration of cells across endothelium through cell junctions |
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chemotaxis |
the directed movement of cells in a concentration gradient |
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phagocytosis by APC |
1.bacterium binds to receptor on phagocyte 2. phagocytosis-bacterium is engulfed by cell membrane 3. bacterium inside the cell vesicle (phagosome) 4. fusion of lytic granule and phagosome- phagolysosomes 5. digestion of bacterium by enzymes 6.transport of bacterial fragments to cell surface 7. release of waste materials |
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cytokines |
small proteins that are made by cells, and function to change or to communicate with other cells |
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chemokines |
cytokines that are used for attracting other cells to the site of infection |
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interleukins |
cytokines that alter the function of other cells |
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how do phagocytes know to attack and kill pattern recognition receptors |
toll like receptors TLR recognize different molecules from pathogens |
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Triggering TLRs leads to chemokine release |
calls in help from the ciculation |
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Triggering TLRs leads to proinflammatory cytokine release |
activates neighbouring cells |
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Triggering TLRs leads to increased microbiocidal activity |
destroy ingested pathogens |
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bacteria fighting back |
1. evasion of phagocyte binding 2. bacterial resistance to phagocytosis- can kill phagocytes 3. some microbes can even grow in phagocytes, some prevent phagosome-lysosome fusion |
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antigen |
a substance, usually foreign, capable of provoking an immune response ex. bacteria, virus, protozoa,etc. |
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epitope |
the specific site on an antigen recognized by immune cells or antibodies |
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antibody- immunoglobulin or lg |
protein produced by B lymphocytes that recognizes a specific epitope on an antigen leads to removal of that antigen |
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complement (c) system |
a group of serum proteins produced by the liver in the circulation to defend against pathogens |
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three complement pathways |
1. classical 2. alternative 3. lectin 3 ways to activate complement cascade |
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how does complement work? |
complement kills pathogens in the blood circulation by cells lysis it does this by creating a MAC |
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MAC Membrane attack complex |
forms a pore structure which allows fluid (water) to move freely across membrane and osmotically lyse the cell |
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classical pathway |
triggered by antigen-antibody complex |
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alternative pathway |
triggered by lipid-carbohydrates (LPS) |
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Lectin pathway |
triggered by mannose |
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C products C3b |
opsonization- coats bacteria to enhance phagocytosis |
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C products C5a |
chemoattractant- recruits phagocytes |
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C products C3a and C5a |
anphylatoxins- cause histamine release |
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C5-C9 |
membrane Attack complex- kills pathogens |
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interferons IFN |
produced by virally activated cells defence molecule against virus |
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antimicrobial peptides (AMPs) |
production triggered by activation of TLRs broad spectrum |
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AMP example |
dermcidin- produced by sweat glands defensins- produced by neutrophils and macrophages thrombocidin- produced by platelets |
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acute phase proteins |
produced in the liver during infections: levels indicate infection |
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C- reactive protein |
marks bacteria for enhanced phagocytosis- opsonization |