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28 Cards in this Set
- Front
- Back
innate immunity
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present beofre exposure to pathogens, effective from birth
mostly nonspecific, quickly recognize and respond to broad range of microbes (regardless of identity) external barriers (ex. skin) and internal cellular and chemical defenses |
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acquired immunity
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develops after exposure to inducing agents, highly specific, use lymphocytes to recognize
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lymphocytes
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white blood cells that produce hormonal and cell-mediated responses
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antibodies
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secreted from B lymphocytes, bind to microbes and mark them for elimination
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lysozyme
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enzyme that digests the cell walls of many bacteria
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external defenses
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skin, mucous membranes lining the digestive, respiratory, and genitourinary tracts
oil and sweat glands give skin a low pH, also low pH in stomach |
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mucus
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viscous fluid that traps microbes and other particles
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phagocytosis
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the ingestion of invading microorganisms by certain types of white blood cells called phagocytes
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phagocytes
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cells that produce certain antimicrobial proteins and help initiate inflammation, which can limit the spread of microbes in the body
attach to their prey via surface receptors |
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4 types of white blood cells (leukocytes) that are phagocytic
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neutrophils, macrophages, eosinophils, dendritic cells
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neutrophils
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most common phagocytic leukocytes, attracted to infected tissue, short life span
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macrophages
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develop from monocytes: transformed into macrophages after a few hours
some migrate, others reside permanently in the spleen, lymph nodes, and other tissues filter microbes in the lymphatic system |
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eosinophils
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defend against multicellular parasitic invaders, discharge enzymes to attack invaders
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dendritic cells
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ingest microbes, stimulate the development of acquired immunity
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complement system
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about 30 serum proteinsthat function in innate defense
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interferon
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provide innate defense against viral infections
infected body cells secrete and induce neighboring cells to produce other substances that inhibit viral reproduction not virus specific |
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defensins
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antimicrobial proteins, secreted by macrophages, damage broad groups of pathogens by various mechanisms without harming body cells
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inflammatory response
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mast cells release histamine, promote blood flow to injured site, results in redness and heat
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histamine
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chemical stored in mast cells, trigger dilation and increased permeability of capillaries
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mast cells
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in connective tissues, relase histamine when injured
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chemokines
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small proteins that direct the migration of phagocytes and signal tem to increase production of microbe-killing compounds
secreted by many cell types |
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natural killer (NK) cells
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patrol the body and attack virus-infected body and cancer cells
once attached to cell, releases chemicals that lead to the death of the stricken cell by apoptosis (programmed cell death) |
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cytokines
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proteins that help activate lymphocytes and other cells of the immune system
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antigen
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any foreign molecule that is specifically recognized by lymphocytes and elicits a response from them, large molecules, either proteins or polysaccharides
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epitope
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small, accessible portion of an antigen that is recognizable by lymphocytes, many types that can induce different responses
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B lymphocytes (B cells)
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type of lymphocyte
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T lymphocytes (T cells)
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type of lymphocyte
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antigen receptors
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antigen-specific receptors embedded in plasma membranes of the B or T cells
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