Action Potentials
repolarisation
+30mV to less than -70mV sodium voltage gated channels closed - inactive potassium voltage gated channels open potassium diffuses out of the cell
threshold potential
-55mV
Threshold
-55mV initiates action potential some voltage gated channels open sodium diffuses into the cell
depolarisation
-70 to +30mV all sodium voltage gated channels open more sodium diffuses into the cell
resting membrane potential
-70mV need a small change in ion distribution across the membrane before an action potential is defiantly going to occur
two processes occur that end depolarisation
1 . inactivation of the sodium voltage gated channels 2. opening of potassium voltage gated channels
action potentials result from
a rapid change in the permeability of the neuronal membrane sodium and potassium ions the permeability changes as voltage gated ion channels open and close
where is the action potential initiated
axon hillock
action potential
neurons communicate over long distances by generating and sending electrical signal or nerve impulses is a large change in membrane potential from a resting value of about -70mv to peak value of +30mV and back to -70mV
hyperpolarisation
restore potential back to -70mV sodium potassium pump working sodium voltage gated channels closed potassium voltage gated channels closed