CHEM-UA 109 Lecture Notes - Lecture 14: Sodium Channel, Gamma-Aminobutyric Acid, Myelin
16 Aug 2016
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Made of schwann cell that wraps its way around the axon. Node of ranvier message jumps from spot to spot. Neuron is a salty banana na+ on outside, k+ on inside. Channels that allow sodium and potassium to pass. Should have a lot more sodium (+) on outside than on inside + large negative particles make inside more negative. Something will happen to trigger channels and open them. Sodium will flow inside neuron changes voltage (no longer -70, now like -50 mv) Opens up next sodium channel along the way: get a flow (cascade) of sodium. Now outside is negative, outside is positive. Sodium channels close, potassium channels open: k+ flows outside repolarization. At rest = -70 mv (- inside, + outside) Depolarize =reaches past threshold gets action potential (-55 mv) Complete depolarization = all sodium channels open then inactivate, later activates k+ by generating new gradient.
