PSYC 3 Lecture Notes - Lecture 4: Rate Equation, Saltatory Conduction, Myelin
Document Summary
Channels in the cell membrane that allow for the passafe of particular ions either in or out of the cell. Ion channels that open in response to changes in membrane potential. V-d na+ channels require depolarization to open. V-d k+ channels are less sensitive require more depolarization to open. 70mv to +40mv the k+ channels open slightly later. Once threshold is reached na+ channels open and na+ rushes into the cell. At height of ap na+ channels become refractory. No more na+ entering and k+ is still leaving the cell. The outflow of cations returns the membrane back to resting overshoot. Inside of cell is now depolarized so k+ leaves the cell. K+ will start leaving slowly but then quickly because diffusion is only working on. Even though leaving, its being overshadowed by na+ it, no longer both diffusion and electro.
