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19 Cards in this Set
- Front
- Back
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What is innate immunity?
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Innate immunity is the defense mechanism that is in place before infection. It is fast, and does not have a "memory" feature. The major players are epithelial barriers and phagocytic cells.
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What is adaptive immunity?
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This is the body's defense mechanism that is produced in response to infection. It is delayed and has a "memory" system. The two major players are B and T lymphocytes.
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What is the main role of cytokines in the immune system?
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Communication. Cytokines are proteins produced by many cell types that mediate the immune response. They link the adaptive and innate immune responses together.
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Name the five initial physical barriers that pathogens encounter.
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"GERMS"
1. Gut peristalsis 2. Epithelium/Endothelium tight junctions 3. Respiratory tract cilla 4. Microflora (normal) 5. Snot (mucins in mucus) |
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Name the 8 initial chemical barriers that pathogens encounter.
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"PALS"
1. Plasma proteins 2. Acidic pH, Antimicrobial peptides, Apolactoferrin, and Antibodies (Immunoglobins) 3. Lysozyme and Lactoferrin 4. Surfactants |
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Name some places where acidic pH can serve as a chemical barrier to pathogens. How does acidic pH serve as a barrier?
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Acidic pH serves as a chemical barrier in the skin, stomach, urine, vagina and bile. It prevents microbial growth.
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Name two main antimicrobial peptides in the body.
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defensins and cathelicidins
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What cells secrete antimicrobial peptides? How do they function as a chemical barrier to pathogens?
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Epithelial cells in the skin, GI tract, and respiratory tract secrete antimicrobial peptides. They are directly toxic to microbes and also recruit leukocytes.
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How do lysozymes serve as a chemical barrier to pathogens?
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Lysozymes serve to hydrolyze peptidoglycan in bacterial cell walls.
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Name three places where lysozyme is commonly found. What types of cells is it found in?
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Lysozyme is secreted by epithelial cells of mucous membranes, moist epithelial linings and many exocrine glands (in tears, saliva, breast milk, GI and GU tracts). They are also found within lysosomes of monocytes, neutrophils, macrophages and hepatocytes.
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What is Lactoferrin? How does it serve as a chemical barrier to pathogens?
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Lactoferrin is made my the same cells and found in the same locations as lysozymes. It inhibits bacterial growth by binding free Fe2+.
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What is apolactoferrin?
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Apolactoferrin is lactoferrin without the Fe2+, it binds lipoproteins on epithelial cells that are used by some viruses as attachment receptors, therefore blocking viral entry.
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How does surfactant serve as a chemical barrier to pathogens? Where is it found? Where is it most concentrated?
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Surfactant protein A (SPA) binds directly to the surface of bacteria, virus and fungi to increase phagocytosis. It is secreted by respiratory epithelium and concentrated in alveoli.
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Who produces antibodies? What are antibodies also known as? Name four places they are located in.
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Antibodies (Immunoglobulins) are produced by B lymphocytes. They are located in tears, mucus, serum and breast milk.
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Who secretes plasma proteins?
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Plasma proteins are constitutively secreted by hepatocytes.
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What causes levels of plasma proteins to increase? What are the two main functions of plasma proteins?
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Plasma protein levels increase rapidly during infection in response to cytokines. They bind to bacterial membranes and membranes of apoptotic cells and activate the "complement pathways" and opsonize.
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C-reactive protein (CRP) and serum amyloid P (SAP) are:
A. Antimicrobial peptides B. Plasma proteins C. Acute phase reactants D. Both B & C |
D.
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What does MBL stand for and what does it bind to? What does it do?
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MBL stands for mannose binding lectin and binds to the surface of bacteria, viruses, fungi and protozoa. It is a plasma protein that activates complement pathways and opsonizes.
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What are the main functions of complement proteins?
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Complement proteins bind directly or indirectly (through CRP, SAP, MBL or antibodies) to surface of cells or pathogens and opsonize, recruit phagocytic cells, and are able to cause direct lysis.
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