NEUR 2500 Lecture Notes - Lecture 4: Potassium Channel, Resting Potential, University Of Manchester
Document Summary
The voltage across the neuronal membrane at any moment in time. The steady equilibrium potential achieved when the membrane is permeable only to sodium ions. Only the membrane potential changes during and action potential. During the resting state, is the neuronal membrane permeable to sodium? no. Briefly explain what happens during an action potential. Na channels open and na rushes into the cell. Large sodium current takes the membrane potential from negative towards ena. During the early part of the action potential, the influx of sodium ions across the membrane briefly depolarizes the membrane. These voltage gated sodium channels close after 1 msec. Membrane repolarization is the result of potassium efflux, which is the outward current because of the opening of potassium voltage gated channels after 1msec delay. The generator potential must reach critical level (threshold) before the axon will generate an actionpotential. This influx of sodium results in depolarization of the membrane.
