ch 11 pt 2

  1. In a voltage gated channel, what happens when the threshold (-55mV) is reached?
    Na gates open and Na starts to enter
  2. What happens when the Na channels are closing?
    K channels are opening and K is leaving the cell
  3. Will the gates respond at -25mV?
    yes (depolarization) The gates will open
  4. In the fourth stage of voltage gated channels, what is the slight overshoot?
  5. The period of a lack of activity occurs for how long? What is the length traveled?
    1-2 minutes; 1 mm of axon length
  6. What is the absolute refractory period?
    • The period from the opening of Na channels until they begin to reset to original state.
    • Na is open and Na is entering.
    • Follows stimulation during which no additional action potential can be evoked.
    • Absolutely nothing can happen!
  7. What is the relative refractory period?
    • Follows absolute refractory period.
    • Interval when a threshold for action potential stimulation is elevated.
    • Na has returned to resting state, some K is still open (and K is still leaving), repolarization is occurring.
  8. What are the 2 refractory periods (in order)?
    absolute & relative
  9. What are the factors that affect conduction velocity? How so?
    • Size (the bigger the axon, the more conductive)
    • Myelination (the more myelinated, the more conductive)
  10. What are the 2 methods of conduction?
    continuous conduction & saltatory conduction
  11. What is continuous conduction? Is it for myelinated or unmyelinated fibers?
    • Unmyelinated.
    • Threshold voltage in trigger zone begins impulse.
    • Chain reaction (walking slowly and deliberately) of opening of Na channels...adjacent to adjacent to adjacent.
  12. How fast does continuous (impulse) conduction occur?
    2 m/s
  13. What is saltatory conduction? Is it for myelinated or unmyelinated fibers?
    • Myelinated.
    • Skipping parts to go faster (walking normally).
    • Skipping from node to node (excessive channels at nodes of ranvier).
  14. How fast does saltatory conduction occur?
    120 m/s
  15. Is pain transmission happens down a myelinated or unmyelinated axon?
    unmyelinated (takes a while for the pain to register)
  16. Why do large fibers have a higher velocity of nerve signal?
    More surface area for signals.
  17. Small, unmyelinated fibers travel at what speed?
    0.5 - 2 m/s
  18. Small, myelinated fibers travel at what speed?
    3 - 15 m/s
  19. Large, myelinated fibers travel at what speed?
    up to 120 m/s
  20. You pull your hand away from a hot stove even before the pain sets in. This is an example of...
    myelinated fibers
  21. A junction that mediates information transfer between neurons or between a neuron and an effector cell.
  22. What is toward (before) the synapse?
  23. What is away from (after) the synapse?
  24. What have neurons that are electrically coupled via protein channels and allow direct exchange of ions from cell to cell (e.g from one muscle cell to another)?
    Electrical synapses
  25. Specialized for release and reception of chemical neurotransmitters
    chemical synapses
  26. What are the 3 ways in which neurotransmitter effects are terminated?
    • degradation
    • reuptake
    • diffusion
  27. Prozac is an example of _____ (terminated neurotransmitter effect)
  28. ______ is the termination of neurotransmitters by enzymes; postsynaptic cell or within the synaptic cleft
  29. ______ is the termination of neurotransmitters by astrocytes or the presynaptic cell
  30. ______ is the termination of neurotransmitters away from the synapse
  31. What are the 3 synaptic regions?
    • axosomatic (axon-body)
    • axodendritic (avon-dendrite)
    • axoaxonic (axon-axon)
  32. ____ junctions are important for electrical synapses.
  33. These 2 muscle types are involved in electrical synapse.
    smooth & cardiac
  34. What mediate, modulate, and alter graded potentials on the postsynaptic cell? They can be ______ or _____.
    neurotransmitters; excitatory or inhibitory
  35. What are the two types of summation be the postsynaptic neuron?
    temporal and spatial
  36. Which summation is the response to successive releases of NT?
    temporal sumamtion
  37. Which summation is the postsynaptic cell stimulated at the same time by multiple terminals?
    spatial summation
  38. When a presynaptic cell is stimulated repeatedly or continuously, enhancing the release of NT.
    synaptic potentiation
  39. Another neuron inhibits the release of excitatory neurotransmitter from a presynaptic cell.
    presynaptic inhibition
  40. presynaptic inhibition causes postsynapse to _____.
  41. a NT acts via slow changes in target cell metabolism or when chemicals other than NT modify neuronal activity
  42. bringing RMP closer to polarization is _____
  43. moving RMP farther from threshold (hyperpolarization) is ______
  44. _____ is when it didn't make it threshold, goes back to RMP (no summation occurs)
  45. In summation, the synapse is stimualtd a second time shortly after the first, adding them together to pass the threshold.
    temporal summation
  46. In summation, the synapses are simultaneously stimulated, adding them together allows them to pass threshold (E1 + E2)
    spatial summation
  47. Hyperpolarization occurs, inhibition causes it to become more negative; no consequential
    spatial summation of EPSP and IPSP
  48. In inhibition, ___ leaks in causing it to become more negative (hyperpolarization)
  49. Negative ions flowing in is (inhibitory or excitatory)
  50. Positive ions flowing in is (inhibitory or excitatory)
  51. What are some examples of chemical classes of NTs?
    • ACh
    • Biogenic Amines
    • Amino Acids
    • Peptides
    • Novel messengers
  52. What are the functional classes of NTs?
    • excitatory or inhibitory effects
    • direct or indirect effects
  53. What decides excitatory vs inhibitory---the receptor or the NT?
  54. What are some types of NTs?
    • ACh
    • GABA
    • Glycine
    • Aspartic Acid
    • Glutamate
    • Monoamines
    • substance P
    • CCK
    • beta-endorphine
  55. What are the 2 main types of NT receptors?
    • channel-linked
    • G protein-linked
  56. Classical receptors mediate direct transmitter action and result in brief, localized changes
  57. second messenger receptors mediate indirect transmitter action resulting in slower, more persistent, and often diffuse changes...they alter intermetabolism of the cell
    g protein-linked
  58. What is the time from arrival of nerve signal at synapse to start of action potential in postsynaptic cell? How long is it?
    synaptic delay; 0.5 msec
  59. The ____ synapses, the longer it takes.
  60. What are 3 kinds and examples of synapses with different modes of action?
    • excitatory cholinergic synapse = ACh (think msucles!)
    • inhibitory GABA-ergic synapse = GABA (keeps us from doing crazy things)
    • excitatory adrenergic synapse = NE (can also be inhibitory)
  61. In excitatory cholinergic synapse, ___ floods in. Triggers release of ___ which crosses the synapse.
    calcium; ACh
  62. The excitatory adrenergic synapse acts through ______ systems.
    2nd messenger (cAMP)
  63. What are the 3 effects of cAMP?
    • 1. binds to ion gate inside of membrane
    • 2. activates cytoplasmic enzymes
    • 3. induces genetic transcription & production of new enzymes
  64. ____ receptors trigger opening to allow Cl- in
  65. Excitatory adrenergic synapse is responsible for enzymatic ______.
  66. Functional groups of neurons that integrate incoming information from receptors and relay the information to other areas
    neuronal pools
  67. What are the are the 2 different zones of neuronal pools?
    • facilitated zone
    • discharge zone
  68. What are the 4 types of circuits?
    • Diverging
    • Converging
    • Reverberating, oscillating
    • Parallel after-discharge
  69. Which 2 circuits are common in sensory and motor pathways?
    Diverging & converging
  70. What type of circuit is this?
    Image Upload 2
    parallel after-discharge
  71. What type of circuit is this?
    Image Upload 4
    converging (sources)
  72. What type of circuit is this?
    Image Upload 6
    diverging (pathways)
  73. What type of circuit is this?
    Image Upload 8
    reverberating, or oscillating
  74. Which circuit keeps the impulse going on and on and involves a sense of time (prediction)?
  75. Which circuit has a more synaptic delay and mutple summations (strengthening the arrangement)?
    parallel after-discharge
  76. What is exemplified by spinal reflexes--sequential stimulation of the neurons in a circuit.
    serial processing (one before the next, before the next, before the next)
  77. What are the 2 patterns of neural processing?
    serial and parallel
  78. What results in inputs stimulating many pathways simultaneously and is vital to higher level mental functioning?
    parallel processing (going on at the same time)
  79. If you bother the cell body enough, it will _____.
  80. Axons will grow back where they were _____.
  81. What is chemically guided?
  82. The strongest "sprout" is the one that ______.
  83. Image Upload 10
    normal nerve fiber
  84. Image Upload 12
    early regeneration
  85. Image Upload 14
    injured fiber
  86. Image Upload 16
    late regeneration
  87. Image Upload 18
    regenerated fiber
  88. What are the 6 steps of regeneration of pns fibers?
    • 1. normal nerve fiber
    • 2. injured fiber
    • 3. degeneration of severed fibers
    • 4. early regeneration
    • 5. late regeneration
    • 6. regenerated fiber
  89. The regeneration of PNS fibers is guided by what?
  90. Memory and behavior have a ____ basis.
  91. What happens while we are sleeping? It involves making more synapses, better synapses, and getting rid of old synapses.
    synaptic potentiation
  92. What are the 3 types of memory?
    • Immediate
    • short-term
    • long-term
  93. What are the 3 ways of getting from short term memory to long term memory?
    • arousal
    • repetition
    • association
  94. Which memory involves what is going on right now (putting a noun and verb together).
    immediate memory
  95. Which memory involves a minute to an hour ago (what you had for breakfast).
    short-term memory
  96. Which memory involves remembering a year, month, etc ago?
    Long-term memory
Card Set
ch 11 pt 2
ch 11 pt 2