1. cidp
    chronic inflammatory demyelinating polyneuropathy
  2. where are NT in a cell located?
    axon terminals
  3. the conducting fiber
  4. myelin used for?
    speeding transmission of signal
  5. what percentage of dry mass are lipids?
  6. excitatory and inhibitory NT?
    • glutamate (excite)
    • GABA (inhibit)
  7. what arthropoda has it?
    • crustacea (shrimps)
    • annelida (earthworms)
  8. is it thicker in CNS or PNS?
  9. gnathostomata
    jawed vertebrate includes reptiles, aves (finches), mammals, amphibian, osteichthyes (trouts), chondrichythyes (sharks and rays)
  10. what does loss of myelin cause?
    slowing of conduction by interrupting localized current flow
  11. where are sodium channels located
    at nodes of rangier
  12. why are myelinated axons faster in electrical transmission?
    action potential at one point along unmyelinated axon produces current that only propagates short distance
  13. how does myelination reduce electrical transmission
    myelin reduces effective conductance and capacitance of internal axolemma
  14. axolemma
    cell membrane surrounding an axon
  15. as schwann cells wrap around axon, what happens to its organelles
    squeezed to the outside
  16. propagation
    repeating of action potential down the axon
  17. paranodal
    next to node
  18. glial axonal junctions
    junction between glial and axon membrane (points of contact)
  19. schmidt-lantermann incisure
    • small pockets of cytoplasm left behind during the Schwann cell myelination process
    • create communication channels between outer layer and inner layer
  20. periodicity
    • white space is greater in PNS than in CNS
    • white is residual cytoplasm
  21. interlamellar tight junctions (radial component)
    firm adhesion between membranes in the internode and as permeability barrier
  22. difference between PNS and CNS sheaths
    • PNS: sheaths are separated by collagen (SC outside sheath)
    • CNS: sheaths are almost continuous looking
  23. major dense lines
    • formed by cytoplasmic faces of the plasma membrane 
    • dark in electron micrographs, b/c osium metal is dense, binds to cytoplasm
  24. intraperiod lines
    cytoplasm forms the major dense lines and the two external surfaces form the myelin intraperiod lines
  25. major proteins in CNS and PNS
    • CNS (PLP) multipass
    • PNS (P0) single pass
  26. where is myelin basic protein located (MBP) and what are its characteristics?
    • in cytoplasm
    • isoelectric 
    • easily dissociated from membrane
  27. difference between schwann and oligodendrocytes
    one oligodendrocytes form many myelin sheaths (may be not next to each other)
  28. why do multiple sclerosis occur?
    b/c immune cells attack the antigens on oligodendrocytes
  29. turnover myelination
    keep getting made
  30. amyelination
    no myelin
  31. dysmyelination
    myelin not compacted correctly, poor contact between myelin surfaces
  32. primary demyelination
    myelin targeted then other structures go with it
  33. secondary demyelination
    neurons dies first, then myelin destroyed
  34. gray matter
    where cell bodies are
  35. wallerian degeneration
    where nerve fiber is crushed or cut, in which part of the axon separated from the neuron's cell body degenerates distal to the injury
  36. what are acquired disorders?
    guillain barre and CIDP (chronic form of guillain barre)
  37. EAE
    • experimental form in mice that mimics MS
    • EAN (mimic Guillian Barre)
  38. genetic disorders
    PLP, P0, PMP22, Cx32
  39. how does inflammation cause demyelination?
    cytokine overproduction via the up regulation of tumor necrosis factor or interferon
  40. compact myelin where?
  41. schwann cell microvilli
    at node of Ranvier
  42. glial axonal junction located where?
  43. voltage gated K channels where
    • juxtaparanode
    • first appear at nodes, then move to paranode and then juxtaparanode
    • important for dampening excitability (only mature fibers conduct fast enough to make them unneeded)
  44. voltage gated Na+2 where?
  45. what does K channels in mature juxtaparanodes functionally may do?
    protect fibers in case of partial de-myelination
  46. how can lipids be separated from other proteins?
  47. protein be separated?
    mass, charge
  48. lysolecithin
    dissolve membrane by digesting it
  49. hexachlorophene
  50. what is one why to measure myelin metabolism?
    labels, turnover
  51. what is isolated myelin
    • separated b/c of high lipid content
    • myelin will float higher in sucrose gradient
    • internodal, compact myelin
    • simple composition, few proteins
    • (you ignore junction myelin b/c they are more protein rich)
  52. what kind of proteins does myelin at junction have?
    • CASPR
    • contactin (gap junction)
    • NF155
    • CAMs proteins (cell adhesion molecule)
  53. NF155
    link loop to axolemma in paranode
  54. E-cadherin
    • link terminal loops together
    • adheren junction (occur at cell cell in epithelial tissues)
  55. MS
    • node elongation with loss of NF155 may allow extracellular current flow to juxtaparanode
    • may cause redistribution of Kv1, Na voltage and Caspr
    • myelin retraction
    • paranodal loop eversion (flip inside out)
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