This preview shows pages 1–3. Sign up to view the full content.
This preview has intentionally blurred sections. Sign up to view the full version.View Full Document
Unformatted text preview: long-distance signals that do not decrease in strength; in neurons , nerve impulses o only axons can generate action potentials (total change in voltage inside neuron of ~ 100mV (from -70mV to +30mV))- depolarization: inside of cell becomes less negative (e.g.: -70mV -50mV)- hyperpolarization: inside of cell becomes more negative (e.g.: -70mV -90mV) Action Potential:- resting state: voltage-gated channels closed; diffusion of sodium & potassium ions through leakage channels- depolarizing phase: increase in sodium permeability & reversal of membrane potential o local influx of sodium leads to slight depolarizations o fast sodium channel activation gates open quickly & sodium rushes into cell o more sodium channels open - positive feedback cycle o if threshold voltage (generally between -50mV & -55mV) is reached by sodium influx, all sodium channels open & action potential is generated o voltage inside cell becomes positive (about +30mV) page4...
View Full Document
- Fall '10