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10 Cards in this Set
- Front
- Back
First line of defense?
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First line of defense are barriers that shield interior of body from external surroundings
Anatomical barriers include skin and mucous membranes Provide physical separation Membranes bathed in antimicrobial secretions |
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What do sensor systems do?
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Sensor system singles when first line barriers have been breached
Two important groups of receptors Toll-like receptors and NOD proteins Complement System |
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what are Toll-like receptors and NOD proteins?
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Found on variety of cells
Recognize families of compounds Enables cells to sense invasion Sends signal to body to respond |
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what is the complement system?
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Acts in response to stimuli
Activation sets off chain reaction that results in destruction or removal of invader |
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What are phagocytes?
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Phagocytes are specialized cells that engulf and digest microbes and cellular debris
Act as sentries Alerted to signs of invasion More phagocytes can be recruited from bloodstream |
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How do cells in the immune system communicate?
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Cell of immune system have elaborate communication system
Communication achieved through productions of proteins Proteins act as chemical messengers Called *cytokines* Cytokines from one cell diffuse to another Bind to cytokine receptor on cell Receptor transmits signal to cell interior Induces changes in cellular activities |
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What happens during inflammation?
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Inflammation is initiated by microbial invasion or tissue damage
During inflammation cells in blood vessels undergo changes that allow certain immune particles to leak out of the cell |
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first line of defense, physical barriers?
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Physical barriers
Skin is most visible barrier Covers majority of surfaces in obvious contact with environment Mucous membranes barrier that lines digestive tract, respiratory tract and genitourinary tract Mucous protest these surfaces from infections |
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Skin?
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Provides the most difficult barrier to penetrate
Composed of two main layers Dermis Contains tightly woven fibrous connective tissues Makes extremely tough Epidermis Composed of many layers of epithelial cells As cells reach surface become increasingly flat Outermost sheets of cells embedded with keratin Makes skin water repellent Outer layers slough off taking microbes with it |
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mucous membranes?
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Constantly bathed with mucus
Helps wash surfaces Some mucous membranes have mechanisms to propel microorganisms and viruses to areas where they can be eliminated |