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22 Cards in this Set
- Front
- Back
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Respiratory System- Respiratory Defense Mechanisms by Jackson
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Respiratory System- Respiratory Defense Mechanisms by Jackson
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What is mucociliary transport?
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particles greater than 5-10 microns don't reach the lower parts of the lung system due to this upward and away movement of the cilia, preventing swallowed particles from getting ot the lungs.
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lysozyme
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breaks up Gram positive bacteria cell wall
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lactoferrin
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removes iron
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Defensins
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small peptides produced by cells in the mucosal membrane that have antibacterial effects, disrupting the microbial membranes. many types.
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What does the normal microbial flora do?
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may contribute to host defense by:
-competing with potential pathogens for binding sites -competing with pot'l pathogens for nutrients -producing antibacterial substances (ie produce antibiotics) |
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What is the primary cell type in the mucociliary transport system?
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ciliated columnar epithelial cells. they have numerous cilia extending from its free surface into the tracheal lumen. there is a layer of mucus (90% water) on top of the cilia.
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What is the respiratory tract mucous membrane made up of?
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epithelium and underlying lamina propria.
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Name some things that can disrupt this respiratory epithelium
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smoking, influenza, primary ciliary dyskinesia (not beating in a coordinated fashion, so not clearing things as they should, leading to a secondary infection)
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Describe the cough reflex
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-Stimulation of irritant receptors
-High pressure forced expiration -Clears excessive mucus -Often diminished in elderly -a backup clearing mechanism |
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What is the last line of defense?
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Resident macrophages in the lungs. they are in alveolar spaces, along the large and small airways, beneath the mucous lining, and interstitially.
they do PHAGOCYTOSIS, antigen presentation, and cytokine production. |
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What do mast cells do?
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found in resp. tract and lung cells. degranulation will release histamine or other pro-inflamm mediators. this action may be IgE mediated or nonspecific factors such as C3a or C5a complement proteins.
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Where is the location for the induction of the immune response?
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in the follicles. Antigens enter and are presented to T and B cells. T cells with specific receptors are being activated here.
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Main antibody class in the mucosal immune system?
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Secretory IgA (sIgA). hey you, don't forget, sIgA does NOT cross the placenta.
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whats in the lamina propria?
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mad cell types. lymphocytes, macrophages, plasma cells making antibody
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how does the plasma cells go from the lamina propria, through the epithelium, to the lumen?
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IgA antibody on the mucosal membranes exists as a dimer (joined via J chain) Secretory component protein is produced by epithelial cells and it acts as a transporter for IgA molecules to get from the lamina propria area, across the epithelial cells, and to the mucosal lumen, and also makes the sIgA less vulnerable to proteolytic digestion.
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What if a patient has a genetic problem in the production of IgA antibody?
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a very common genetic deficiency. it may be completely asymptomatic. There is some compensation in the body. The receptor for IgA can also transport IgM, and IgM transportation will be increased. It's not as good (specific, tight-binding), but it still works.
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Age-related Changes
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↓ Immune cell activation
↓ Response to vaccines ↓ Mucociliary clearance ↓ Cough reflex |
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Anti-viral defenses –
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Type I interferons, NK cells, CD8+ T cells
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Anti-fungal defenses –
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Th1 T cells, Macrophages, Neutrophils
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Anti-parasitic defenses –
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Eosinophils, IgE
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What cytokine does Th1 T cells produce?
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Interferon Gamma. This defines Th1 helper T cells. Interferon Gamma activates macrophages, natural killer cells, etc.
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