The nervous system7-test1.txt

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The nervous system7-test1.txt
2012-02-09 19:53:29
psu BIOL141

PSU Physiology Test1(c7)
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  1. _________ form myelin sheath around peripheral axons in the PNS
    Schwann cells
  2. ___________ support sensory and autonomic ganglia ( ganglia=PNS)
    satellite cells
  3. ________ form myelin sheath around CNS axons
  4. ________ help regulate the external environment of neurons (CNS)
  5. ________ line the ventricles in the brain and the spinal cord (CNS)
    ependymal cells
  6. ________ travel the CNS and "eat" foreign and degenerated materials
  7. some axons in the CNS and PNS are surrounded by ________, which is a fatty layer of insulation
    myelin sheath
  8. Successive wrapping of Schwann cells around axons in the ____ produces myelin sheath.
  9. exposed gaps of myelin sheath used to produce nerve impulses are named nodes of __________
  10. Oligodendrocytes use octopus-like extentions to create _________ around multiple axons in the _____. (AKA white matter)
    • myelin sheath;
    • CNS
  11. The ________ is defined by its tight junction selective molecule diffusion, requiring specific transport methods through the capillaries into the brain.
    Blood brain barrier
  12. The _____________ is significant in preventing drug treatment of degenerative disorders (i.e. Parkinson's). Certain chemicals do not diffuse into the brain properly.
    blood brain barrier
  13. pseudounipolar neurons have one process that splits ('T' shaped). They are _________ neurons
  14. sensory neurons are ________polar neurons
  15. Bipolar neurons have (2) processes, such as in the retina and cochlea (bow-tie shaped). They are ________ neurons
  16. neurons with (2) processes are ________polar neurons
  17. Multipolar neurons have many dendrites but one axon. They are 1: _______ 2: __________ neurons
    • motor;
    • association
  18. Schwann cells "eat" cut(damaged) axons, form a tube, and then a new axon tip grows to fill it out. This is ________, and it occurs in the ___.
    • Regeneration;
    • PNS
  19. myelination = ________ color; non-myelinated axons = ________ color
    • white;
    • gray
  20. L-Dopa is permeable to the ____________ but dopamine is not (Parkinson's).
    blood brain barrier
  21. Step (1) of action potential: ___+ gates open and the __+ diffuses into the cell (starting depolarization)
  22. Step (2) of action potential: ___+ gates open and the __+ diffuses out of the cell (while continuing to depolarize)
  23. resting potential is __ mV
  24. Threshold (potential) is at __ mV
    -30 mV
  25. action potential is at __ mV
    +30 mV
  26. Hyperpolarization is at __ mV
    -90 mV
  27. Na+ gates are deactived at _______ potential
    action potential (to begin repolarization)
  28. depolarization is caused by _____________ into the axon
    diffusion of Na+ in
  29. repolarization is caused by _____________ out of the axon
    diffusion of K+ out
  30. conduction in _________ axons: every surface of axon membrane can produce an action potential
  31. saltatory ("leaping") conduction happens in _________ axons
  32. myelination increases OR decreases action potential conduction?
    increases (due to fewer necessary conduction sites and less "leaking" of charge.)
  33. a stimulus causes positive charges to flow into a cell; this is called __________
  34. a return to resting membrane potential is called _________
  35. Axon resting potential: Permiability ratio of Na+ (out) to K+ (in) is __:__
    3:2 -- 3 Na+ out: 2 K+ in
  36. Na and K gating allows for action potentials because each gate opens at a different _________
    voltage (mV)
  37. once an axon is depolarized to threshold, it will fire. this is the _________________ law
    all-or-none law
  38. increased stimulus strength = __________ action potential frequency
  39. the manditory minimum interval between action potentials is called a _______________ (regulates frequency)
    refractory period
  40. gap junctions are found in ____________ synapses
  41. __________ synapses are when pre and postsynaptic neurons are separated by a synaptic cleft
  42. cardiac muscle is an example of ___________ synapses (gap junctions)
  43. Na+ or Ca+ entering a (post-synaptic) neuron causing graded depolarization for it to become less negative is ___________
    EPSP-- excitatory post synaptic potential
  44. Cl- entering a (post-synaptic) neuron causes graded polarization, making it more negative is ___________
    IPSP-- Inhibitory post synaptic potential
  45. ______ junctions are joined in areas of contact with low electrical resistance. this allows for uniform action potentials in the ____ muscles
    • gap junctions;
    • cardiac
  46. ______________ are little bubbles of neurotransmitters in the axon terminal that dock with SNARE and released by exocytosis (into the cleft)
    synaptic vesicles
  47. action potentials stimulate the entry of __+ into the axon terminal of the pre-synaptic neuron, prompting vesicles to undergo exocytosis into the cleft
  48. NT release: 1-action potential, 2- ___+ channels open, 3- __+ binds (to protein) 4- __+ protein complex stimulates fusion and exocytosis
  49. _________ gated/regulated ion channels require input from something like Ca+ (found in post-synaptic membrane)
  50. _________ gated/regulated ion channels require input from something like a +30 mV charge (found in axon)
  51. While NT binding receptors are specific, certain "toxins" may also activate these receptors. ACh's stimulatory effects (muscle contractions) may be activated by __________
    nicotine (@ the nicotinic receptors)
  52. ACh binds to muscarinic receptors in the heart cells, causing ___-protein to open K+ outward diffusion, which means ____ heart rate (K+ out = polarization/inhibition)
    • G-proteins;
    • slower heart rate
  53. The enzyme ___________ deactivates free ACh at the post-synaptic cell membrane after it "does its job" to prevent further activations (No deactivation = spastic paralysis in muscle; principle of nerve gas)
    AChE (acetylcholinesterase)
  54. Alzheimer's disease is associated with the loss of ___________ neurons, which use ACh as a NT (Tx = AChE inhibitors)
  55. _________ are regulatory molecules derived from amino acids. They are also NT's ( i.e. dopamine, norepinephrine, epinephrine).
  56. monoamine NT's at the synapse are stopped by (1):_________ from the cleft into the presynaptic Neuron, then (2): __________ of the monoamine by an enzyme MAO (monoamine oxidase)
    • reuptake;
    • degredation
  57. two pathways of dopamine NT use in the brain are 1: ______ control, & 2: __________
    • motor control; (nigrostriatal)
    • emotional reward (mesolimbic)
  58. MAO inhibitors prevent reuptake of monoamines, which plays a role in treatment for __________
    depression, Parkinson's
  59. cocaine ___________ reuptake of dopamine
  60. SSRI's prevent reuptake of __________
    5-HT (serotonin)
  61. _________ are inhibitory motor NT's: they hyperpolarize the post-synaptic neuron rather than depolarizing (Opens Cl- channels rather than Ca+)
    Glycine & GABA
  62. Huntington's disease is defined as a loss of motor control. This is because of a deficiency in inhibitory motor NT _____.
  63. Example categories of _________: Amines, amino acids, lipids, gases (Nitric oxide etc) Purines(ATP)
  64. ___________ is the major excitatory NT in the brain (80% of all)
  65. NMDA receptors are involved in ____________ storage
  66. Benzodiazepines are _________ agonists, regulating anxiety.
  67. "runner's high" may be influenced by exogenous ________
  68. _________ acts as a blood vessel dialator. involved in Viagra
    NO (nitric oxide)
  69. ____________ summation is the result of many pre-synaptic neurons converging on the dendrites of a neuron
  70. __________ summation is successive NT release, resulting in the summation of EPSPs in the post-synaptic neuron.
  71. Synaptic potential OR action potential: which does NOT have a refractory period?
    Synaptic potential
  72. the improved ability of a presynaptic neuron that has been stimulated at a high frequency to then stimulate the post-synaptic neuron over a long period of time is __________ (method of neural learning?)
    Long-term potentiation (LTP)
  73. a process where endocannabinoids suppress the release of NT from pre-synaptic neurons. this happens over a long period and inhibits functioning for some time _________
    Long-term depression
  74. _______________ inhibition: the amount of NT released at the end of the pre-synaptic neuron is decreased by a second neuron's signal
  75. _______________ inhibition: induces hyperpolarization in a post-synaptic neuron