Nonspecific Host Defenses

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Nonspecific Host Defenses
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Nonspecific Host Defenses
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Nonspecific Host Defenses
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Prevention of Entrance

• Physical Barriers
• Skin
• Mucous membranes
• Blood clotting
• Movement Out of Body
• Bleeding
• Urinating
• Vomiting
• Diarrhea
• Chemical Defenses
• Lysozyme in tears, sweat, and saliva
• Low gastric pH

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Physical Barriers
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Blood Clotting
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Inhibition within the Body

• Chemical Defenses
• Movement Out of Body
• Chemical Defenses
• Non-Specific Inhibition within the body
• Leukocytosis
• Phagocytosis
• Systemic filtering (e.g., lymph nodes)
• Inflammation
• Fever
• Interferon
• Complement

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Leukocytes WBCs
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Pus
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Phagocytes
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Steps of Phagocytosis

• Steps of Phagocytosis include
• Chemotaxis
• Adherence
• Ingestion
• Digestion
• Pathogens interfere with phagocytosis by
  interfering with these various steps
• Additionally, some pathogens interfere with
  phagocytosis by killing the phagocyte (i.e., from
  inside)

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Phagocytosis
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Interference with Phagocytosis
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Lymph Node
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Spleen
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Inflammation
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Fever
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Fever

• Fevers are induced by Pyrogens produced by either
  microorganisms or body cells
• The high temperature of fever can
• Interfere with pathogen growth
• Can inactivate some pathogen toxins
• Can intensify immune responses
• Forces the host to rest
• Fevers, as a consequence, are not quite the bad
  things most individuals consider them to be
• Usually, only once fevers are at or above 104
  degrees Fahrenheit should one become sufficiently
  concerned to resort to treatment using
  antipyretics

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Interferon
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Complement
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Impact of Complement
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Chemotaxis
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Opsonization
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Membrane Attack Complex
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Link to Next Presentation
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Acknowledgements
http//project
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Interferon