Mediators of Inflammation

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Mediators of Inflammation
2014-12-28 06:04:56

Vet Med - Module 7
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  1. What are the cardinal signs of inflammation?
    Heat, redness, swelling, pain, loss of function
  2. List some of the benefits of inflammation
    • Dilution of pathogens, toxins
    • Killing/sequestering/degrading pathogens, foreign material, necrotic tissue, neoplastic cells
    • Providing wound healing factors
    • Restricting movement allowing time for repair
    • Increasing temperature to inhibit replication of pathogens
  3. List some of the disadvantages of inflammation
    • Excessive or prolonged inflammatory responses can cause:
    • Immune mediated diseases 
    • Hypersensitivity reactions
    • Asthma
    • Lymphplasmacytic stomatitis/fascitis
    • Inflammatory bowel disease
    • Idiopathic pulmonary fibrosis of West Highland White Terriers
  4. What are the two classes of inflammatory mediators?
    Cell derived and plasma derived
  5. Give examples of cell-derived mediators
    Platelets, neutrophils, monocytes/macrophages, mast cells, histamine
  6. Give an example of a plasma derived mediator
    Complement proteins, kinins
  7. Where are plasma derived inflammatory mediators made?
    In the liver
  8. What stimulates mediators of inflammation?
    • Microbial products and necrotic material (PAMPs and DAMPs)
    • Proteins of complement, kinin and coagulation systems
  9. Which cell derived mediators are vasoactive amines?
    Histamine and serotonin
  10. What type of cell is histamine mostly found in?
    Mast cells
  11. What happens when histamine and serotonin are released?
    Dilation of arterioles and increased permeability of venules
  12. What stimulates serotonin release?
    Platelet aggregation
  13. Which cell derived mediators are arachidonic acid metabolites?
    Prostaglandins, leukotrienes (LTs), lipoxins
  14. What are arachidonic acid metabolites derived from?
    Arachidonic acid in the cell membrane
  15. What pathway produces a) prostaglandins b) LTs and lipoxins?
    • a) Cyclooxygenase pathway
    • b) Lipoxygenase pathway
  16. What cell type secretes leukotrienes?
  17. True or false: lipoxins facilitate inflammation?
    False: they INHIBIT inflammation.  Particularly inhibit leukocyte recruitment.
  18. What type of drugs inhibit a) the entire arachadonic acid pathway b) COX-1 and COX-2 pathways?
    • a) Corticosteroids
    • b) NSAIDs
  19. What type of cell mainly produces cytokines TNF and IL-1?
    Activated macrophages
  20. What stimulates the secretion of TNF and IL-1?
    Endotoxin, other microbial products, immune complexes, physical injury, etc
  21. What effects does TNF and IL-1 have after their release?
    Effects on endothelium, leukocytes, fibroblasts, induction of systemic acute phase reactions and FEVER
  22. Give examples of other cell derived mediators
    Chemokines, Platelet activating factor, Reactive oxygen species, Nitric oxide, Lysosomal constituents of leukocytes, neuropeptides
  23. In what form does complement circulate around the body?
    In an inactive form in plasma
  24. Describe the steps involved in complement activation
    • Proteolysis of C3
    • Release of C3a and C5a (anaphylatoxins)
    • Formation of membrane attack complex
    • Result in phagocytosis
  25. What are the three main functions of the complement system?
    • Inflammation
    • Phagocytosis
    • Cell lysis
  26. How does the complement system cause a) inflammation b) phagocytosis c) cell lysis?
    • a) C3a and C5a are released which causes histamine release from mast cells.  This increases vascular permeability and vasodilation.
    • b) C3b act as opsonins and promotes phagocytosis
    • c) deposition of MAC complex on cells causes lysis of cells
  27. What are the three pathways that activate the complement cascade?
    Alternative pathway, classical pathway and lectin pathway
  28. Coagulation begins with factor ... activation?
  29. How does inflammation promote clotting?
    Via production of coagulation factors, makes endothelial surfaces prothrombogenic, inhibits anticoagulation mechanisms
  30. What molecule involved in the coagulation system promotes inflammation?
  31. What are kinins?
    Vasoactive peptides
  32. What effects does bradykinin have after its release?
    Increases vascular permeability, contraction of smooth muscle, dilation of blood vessels and pain
  33. Which kinin is a potent activator of factor XII?
  34. What other kinin is activated by kallikrein?