[Answer] To reach threshold the amount of sodium _______.

Answer: entering the cell must overcome the potassium exiting
To reach threshold the amount of sodium _______.
Threshold potential – Wikipedia
Threshold potential – Wikipedia
Refractory period (physiology) – Wikipedia
Action potential – Wikipedia
The threshold value controls whether or not the incoming stimuli are sufficient to generate an action potential. It relies on a balance of incoming inhibitory and excitatory stimuli. The potentials generated by the stimuli are additive and they may reach threshold depending on their frequency and amplitude. Normal functioning of the central nervous systementails a summation of synaptic inputs made largely onto a neuron’s dendritic tree. These local graded potentials which are primarily associated with external stiā€¦
With the right amount of stimulus it can cause the action potential to reach threshold and cause an influx of sodium during the depolarization phase. After a couple of seconds the membrane potential becomes positive and causes potassium ions to exit the cell during the repolarization phase and go below the threshold level into the …
Depolarization above threshold results in an increase in the conductance of Na sufficient for inward sodium movement to swamp outward potassium movement immediately. If the influx of sodium ions fails to reach threshold then sodium conductance will not increase a sufficient amount to override the resting potassium conductance.
As various drugs and other factors act on the resting potential and bring it closer to the threshold potential an action potential is more easily and rapidly obtained. Likewise when the sodium channels are in a state of greater activation then the influx of sodium ions that allows the membrane to reach threshold potential occurs more readily.
Sun Jul 25 2004 14:30:00 GMT-0400 (Eastern Daylight Time)…

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