PC 705 Module 2 Exam - Immunity and Infection

PC 705 Module 2 Exam - Immunity and Infection Innate Immunity involves which two things? First line of defense (mechanical and biochemical barriers) & Second line of defense (Inflammatory response) What is the first line of defense? Natural barriers or mechanisms to keep invaders OUT Examples of physical & mechanical barriers during the first line of defense? Tight epithelial cells of skin & mucous membranes of GI, GU, and respiratory tract Mucus that coats and traps microorganisms Cilia to help expel pathogens (in nose or throat) Cleansing through vomiting & urination Normal cell turnover or "washing" of surfaces Examples of biochemical barriers during first line of defense? Saliva, tears, earwax, sweat, low pH and temp of skin, low pH in stomach, secretion of antimicrobial peptides What is the second line of defense? inflammatory response Is innate immunity specific or non-specific? Non-specific Is the inflammatory response specific or nonspecific? Non-specific What is normal microbiome? microorganisms that naturally live on or in the body that do not normally cause harm Mutualistic (both benefit) or Commensal relationship (benefits one & doesn't harm the other) When can normal flora become pathogenic? When the opportunity presents "opportunistic" -body integrity is compromised -immune/inflammatory system is defective What are examples of opportunistic infections? E. Coli that naturally lives in the GI tract migrates to the GU tract and causes a UTI Normal vaginal flora becomes overgrown---yeast infections How are bacteria in the gut mutualistic for human hosts? -helps digest fatty acids & polysaccharides -produces biotin & vitamin K -helps absorb ions -helps reduce the ability for pathogenic organisms to take root (competition for nutrients & space) -helps train the adaptive immune response by inducing growth of gut associated lymphoid tissue Normal flora in the Vagina? Lactobacillus Normal flora on the skin? Pseudomonas aeruginosa What are the typical areas where normal flora reside? Skin, mucous membranes of eyes, upper and lower GI, urethra, vagina Normal flora bacteria excrete ammonia, phenols, indoles, and toxic proteins to ultimately do what? inhibit colonization of pathogen How long does acute inflammation usually last? 8-10 days from onset to healing What are the cardinal signs of inflammation? Redness, heat, swelling, pain, loss of function Chemokines released at the site of injury or disruption helps to attract what? Chemotaxis---attracts neutrophils What is the pathophysiology of redness during inflammation? vasodilation, accumulation of RBCs, increased blood flow What is the pathophysiology of warmth/heat during inflammation? Vasodilation, increased blood flow, accumulation of RBC's What is the pathophysiology of swelling or edema during inflammation? Increased capillary permeability (leakage of plasma fluid), increased blood flow, accumulation of neutrophils What is the pathophysiology of pain during inflammation? -Pressure from the fluid accumulation & increased blood flow -biochemical mediators (prostaglandins & bradykinin) -stretching of nocicepters (nerve endings) What is the pathophysiology behind loss of function as the results of inflammation? cell death (necrosis) The result of cell necrosis is specific depending on the tissue or site that is affected. True or False True! -necrosis during myocardial infarction can result in replacement of tissue with a fibrous scar -necrosis in the brain can results in an abscess filled with necrotic tissue -necrosis in the liver can result in regrowth or regeneration of liver cells What are the systemic manifestations of inflammation? Fever, leukocytosis, increased plasma protein synthesis IL-1 is a cytokine? True or false True IL-1 is mainly secreted by which cells? Macrophages and sometimes lymphocytes What are the important mechanisms of IL-1? -induces neutrophils to proliferate and move to the site -since neutrophils are phagocytes--this helps the phagocytosis or "engulfing" of the pathogens -is also an endogenous pyrogen (to cause fever) -when interacting with Helper T cells the release of IL-1 stimulates Helper T cells to release IL-2--which causes the proliferation of B & T cells (lymphocytes) Examples of endogenous pyrogens Tumor necrosis factor alpha & IL-1 What does an endogenous pyrogen do? acts on the hypothalamus to "reset" the thermostat to a higher temperature to help kill bacteria that are temperature sensitive