The larger svmulus produces a larger depolarizavon

Info iconThis preview shows page 1. Sign up to view the full content.

View Full Document Right Arrow Icon
This is the end of the preview. Sign up to access the rest of the document.

Unformatted text preview: enVal can change the ion flow. Graded potenVals and an acVon potenVal in a neuron SVmuli 0 Threshold 0 –50 0 1 2 3 4 5 Time (msec) (a) Graded hyperpolariza0ons produced by two s0muli that increase membrane permeability to K+. The larger sVmulus produces a larger hyperpolarizaVon. Threshold –100 0 1 2 3 4 5 Time (msec) (b) Graded depolariza0ons produced by two s0muli that increase membrane permeability to Na+. The larger sVmulus produces a larger depolarizaVon. AcVon potenVal 0 –50 ResVng DepolarizaVons potenVal ResVng potenVal HyperpolarizaVons –100 +50 Membrane potenVal (mV) +50 Membrane potenVal (mV) Membrane potenVal (mV) +50 –50 Stronger depolarizing sVmulus SVmuli Threshold ResVng potenVal –100 0 1 2 3 4 5 6 Time (msec) (c) Ac0on poten0al triggered by a depolariza0on that reaches the threshold. All ­or ­none Summary of graded potenVals •  Magnitude/duraVon varies with magnitude/duraVon of trigger •  Decremental conducVon •  Passive spread to neighboring inacVve membrane •  No refractory period •  Can be addiVve •  Can cause a depolarizaVon or hyperpolarizaVon event...
View Full Document

Ask a homework question - tutors are online