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Cards In This Set
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GPs are generated in __________ and spread to the __________ to initiate AP that travels down the axon.
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Dentrides/cell bodyAxon hillock/triggering zone
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Two types of propagation
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1. Contiguous2. Saltatory
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Contiguous conduction
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Action potential spreads along every portion of the membrane ("touching")Seen in unmyelinated fibersSlower
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Saltatory conduction
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Impluse jumps over sections of the fiber covered with myelin
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Rapid conduction in ___________ fibers
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Myelinated
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Myelin
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Lipid covering that insulates the axon (white matter)Formed by oligodendrocytes in CNSFormed by schwann cells in PNS
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Nodes of ranvier
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Gaps in myelin where bare axon is exposed to ECFContains voltage gated K and Na channels
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Neurotransmitters
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Carry signals across the synapseVary from synapse to synapseSame neurotransmitter is always released at a particular synapseQuickly removed from synaptic cleft
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Synaptic Transmission Events (1-7)
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1. AP propagated to axon terminal2. Voltage gated Ca channels open3. Ca diffuses into SEB from ECF4. NT is released via exocytosis into synaptic cleft5. NT binds to receptors on subsynaptic membrance6. Ion channels open on subsynaptic neuron7. Fate of neurotransmitter (diffuse away, degraded by enzymes or reuptake by presynaptic neuron)
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Signals at synapse either ________ or ________ the postsynaptic neuron
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ExcitesInhibits
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Two types of synapses
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Excitatory and Inhibitory
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Excitatory synapses
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Binding of NT moves membrane potential closer to thresholdEPSPs
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Inhibitory synapses
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Binding of NT moves membrane potential farther from thresholdIPSPs
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EPSPs and IPSPs are GP which can be _____________
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Summated
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Grand post synaptic potentials (GPSPs)
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Sum of all EPSPs and IPSPs that are occurring
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