50 acvon potenval 2 50 100 extracellular uid na

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Unformatted text preview: •  Triggered by sVmulus, neurotransmiper binding receptor, spontaneous shiis ion pump cycles •  Occurs in specialized regions of cell designed to respond to triggering events (cell body) Summary of acVon potenVals All ­or ­none membrane response Always a large depolarizaVon Constant duraVon Propagated throughout membrane without diminishing through regeneraVon in neighboring inacVve membrane •  Refractory period, so unidirecVonal travel •  Occurs in area of membrane with lots of NA+ voltage ­ gated channels (axon) •  •  •  •  The role of voltage ­gated ion channels in the generaVon of an acVon potenVal (layer 1) Membrane potenVal (mV) +50 AcVon potenVal 2 –50 –100 Extracellular fluid Na+ + + Plasma membrane – – – – – – – – Cytosol – – Sodium channel 1 ResVng state 4 Threshold 1 5 1 ResVng potenVal Time AcVvaVon gates Potassium channel + + + + + + + + 3 0 + + – – K+ + + – – InacVvaVon gate Undershoot The role of voltage ­gated ion channels in the generaVon of an acVon potenVal Na+ + + + + + + – – – – + + – – –...
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This note was uploaded on 02/04/2014 for the course BIOG 1440 taught by Professor Owens during the Fall '10 term at Cornell University (Engineering School).

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