Term
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Definition
| A mechanism of defense that does not depend on prior exposure to the invader |
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Term
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Definition
| A mechanism of defense that is specific to the particular no self material, requires time for development, and occurs more quickly and vigorously |
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Term
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Definition
| Skin and mucosal surfaces |
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Term
| Skin (integumentary system) |
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Definition
-oil and sweat glands give skin surface a pH of 3-5
-sweat contains lysozyme which digests bacterial cell wall
-normal flora contain non-pathogenic bacteria and fungi
-epidermis 10-30 cells thick , dermis 15-40 times thicker |
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Term
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Definition
Digestive tract
Respiratory tract
Urogenital tract |
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Term
| Mucosal surfaces- digestive tract |
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Definition
Saliva contains lysozyme
Acidic environment of stomach
Digestive enzymes in intestine
Nonpathogenic normal flora
Vomiting and diarrhea to expel pathogens |
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Term
| Mucosal surfaces- respiratory tract |
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Definition
Pathogens trapped by mucus in bronchi and bronchioles
Climates epithelial cells sweep mucus into the glottis
Coughing and sneezing expels pathogens |
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Term
| Mucosal surfaces- urogenital tract |
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Definition
Vaginal secretions viscous and acidic
Secretions promote growth of normal flora
Acidic urine of both sexes may wash out pathogens |
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Term
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Definition
| Phagocytes, inflammation, complement and interferon, cytokines and chemical signals and anti microbial proteins |
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Term
| Agranulocytosis (mononuclear leukocytes) |
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Definition
Macrophages
-monocytes mature into active macrophages at site of infection
-intracellular killing and digest pathogens via phagocytosis
-phagosome fuses with lysosomes (oxygen containing and nitrogen containing free radicals)
-roam continuously in the extracellular fluid bathing tissues
-antigen spending cell for helper T cells
-respiratory burst for additional killing ability (free radicals) |
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Term
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Definition
Neutrophils
Eosinophils
Basophils |
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Term
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Definition
-most abundant circulating leukocytes
-first cell on site of tissue damage or infection
-intracellular killing via phagocytosis
-large numbers in blood |
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Term
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Definition
-2-5% of the total leukocytes in blood
-important in he elimination of parasite, releases extremely potent mediators
-high blood count is often associated with parasitic infection and allergic diseases
-express Fc receptor molecules for IgE |
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Term
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Definition
-circulating cells, least numerous at about 0.5%
-release mediators such as histamine to promote inflammation
-express Fc receptor molecules for IgE |
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Term
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Definition
Natural killer cells
-do not kill pathogens directly, but induce apoptosis of infected cells
-lease perforins, insert in membrane and make pores, granzymes, enter infected cell and activate caspaze enzymes that induce apoptosis
-big player in immune surveillance and the bodies defense against cancer
-Do not have T cell receptors but do express Fc receptor molecules for IgE
Indirect killing:no phagocytosis |
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Term
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Definition
Primarily located under mucosal surfaces
Release mediators such as histamine to promote inflammation
Also triggered during allergic responses
Express Fc receptor molecules for IgE
Important component of inflammatory response |
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Term
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Definition
Occurs over seconds, minutes, hours, and days
Clinical signals are released by infected or injured cells during initial response to tissue damage
Dialation of local blood vessels increases blood flow at site
Increased permeability of capillaries causing edema
Tissue swelling puts pressure on nerve endings
Macrophages and neutrophils release cytokines interleukin-1 and tumor necrosis factor which act on hypothalamus to raise body temp.
Cell death (necrosis) always occurs to some extent |
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Term
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Definition
Most common sign of infection
Stimulates phagocytosis and causes liver and spleen to store iron and zinc needed by bacteria
May destabilize certain viruses and bacteria |
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Term
| Delayed type hypersensitivity |
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Definition
A type of cell mediated immunity in which the ultimate effectors are activated macrophages
A period of 24 hours or more elapses between the time of antigen introduction and the response to it in an immunized subject
Delay occurs because TH1 cells with receptors for that particular antigen require time to arrive at antigen site, recognize the secrete IL2 TNF and TNF-y |
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Term
| Immediate hypersensitivity |
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Definition
A type of antibody mediated immunity which involves de granulation of basophils and most cells in the area
-basophils and mast cells have receptors that bind to the Fc portions of antibody
-when exposed to the same allergen a second time de granulation occurs
-suits in dilation of local blood vessels and increased permeability,edema
-important in some parasite infections
- basis of allergies and asthma |
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Term
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Definition
Systemic immediate hypersensitivity produced by exposure to further doses of the same protein, usually when exposure is within less than two weeks
Basophils and mast cells release pharmacologically active substances
Widespread rapid inflammatory response that may be fatal |
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Term
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Definition
| acute inflammation that fails to heal; occurs over longer times and is disease related |
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Term
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Definition
| arises from abnormal and continuous wound repair processes that fails to terminate resulting in elevated levels of collagen and scaring |
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Term
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Definition
| nodules of inflammatory tissue that may accumulate around persistent antigen |
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Term
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Definition
| when necrotic debris confined to a localized area forms pus that may cause and increase in hydrostatic pressure |
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Term
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Definition
| an area of inflammation that opens out to a skin or mucous surface |
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Term
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Definition
1. consists of approx. 30 proteins, along with factors B, D, P
2. circulate freely in blood plasma,generally in inactive form (zymogen)
3. complement can be activated by classical pathway (antigen-antibody complex) or alternative pathway (spontaneously) or lectin pathway (cell wall polysaccardides of certain bacteria and fingi with factors B, D, P)
4.proteins (C3b) coat surface (opsinization) thus promoting phagocytosis and destruction of pathogen by macrophages and neutrophils which have receptors for C3b
5. Complement proteins can form membrane attack complex that form pores in pathogens that have lipid membrane to induce lysis |
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Term
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Definition
1. a class of proteins synthesized upon viral infection of a cell, made by almost all cells
2. act as messengers to protect normal cells initially from becoming infected
3. INF alpha and beta induce the degradation of RNA and block protein production
4. INF gamma is produced by TH cells and NK cells to stimulate cells in cellular response |
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Term
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Definition
1. are protein hormones used by immune cells to communicate
2. can affect same cells that produce them, cells nearby or cells distant in body |
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Term
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Definition
1. ligands may be located on cell surface of neighboring cells, dissolved in blood (cytokines) or on the surface of or secreted by pathogens
2. ligand binds to a specific cell receptor protein initiating intracellular signal cascades
3. cascades may activate transcription factors or proteins that control gene induction, phagocytosis, apoptosis or secretion
ex. JAK-STAT pathway |
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Term
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Definition
receptor
Janus Kinase, Signal Transducer and Activator of Transcriptor by cytokine
activates JAK protein, which adds a phosphate group to receptor |
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Term
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Definition
| proteins that add a phosphate group to other proteins |
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Term
| pattern recognition receptors |
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Definition
| broad specificity that bind to molecules on the surface of pathogens; stimulated by PAMPs |
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Term
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Definition
| pathogen-associated molecular patterns: small molecular motifs conserved within a class of pathogens |
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Term
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Definition
| bind lipoproteins and lipopolysaccharides from bacterial cells inducing Gram positive bacteria (lipoleichoric acid) and Gram negative bacteria |
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Term
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Definition
| integral membrae proteins that recognize fragments of complement and mediate various defense functions, including phagocytosis |
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Term
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Definition
single, membrane-spaning non-catalytic receptors usually expressed in sentinel cells such as macrophages and dendritic cells, that recognize structurally conserved molecules derived from microbes
activate immune cell responses |
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Term
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Definition
non-self recognition
antigen specific
systemic response: immunity is not restricted to initial infection site
"memory" |
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Term
| Major Histocompatibility Complex |
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Definition
| cell surface glycoproteins, highly polymorphic |
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Term
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Definition
present on every nucleated cell of the body
cytotoxic T cells (CD8) respond to endogenous antigen bound to MHC class I |
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Term
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Definition
found only on antigen presenting cells (macrophages, B cells, and dendritic cells)
TH cells (CD4)respond to exogenous antigen bound to MHC class II proteins |
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Term
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Definition
| entirely associated with cell surfaces, t-cell receptors, that are unable to see free antigens |
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Term
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Definition
regulate the immune responses of other cells or directly attack cells that carry specific antigens
-lymphocytes produced in red bone marrow, migrate the thymus (primary lymphoid organ) where they mature (VDJ recombination of T cell receptor) and undergo selection
-T cells must recognize self MHC proteins needed for activation but not the self antigens (self tolerance) that the MHC presents (T-cell eliminated in thymus if criteria not met)
-"naive" t cells recirculate only between the blood and lymphoid organs, do not enter other tissues; activated in secondary lymphoid organ
-t cell receptors are transmembrane proteins with constant and variable region, like antibodies; composed of 2 chains
- t cell receptors recognize only a processed peptide fragment precented by APC's MHC molecule to tge B cell receptors |
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