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Question:
dianaa
Student
High School - 12th Grade
Could someone please help explain the terms used in action potential?? The text book terminology isnt helping at all!
Biology 30.
polarized, depolarized, hyperpolarized, refractory period, repolarized and threshold level.
thanksss!
Answers:
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hart379 Teacher
High School - 10th GradePosted by hart379 on Sunday October 4, 2009 at 9:44 AMWhen a neuron (nerve cell) is stimulated there is something called an all-or-none response. That means that the stimulation that the nerve receives has to have a minimum strength in order to be felt at all. That minimum strength is called the threshold. For example, if you have a long line of dominos and you very gently tap the first domino, nothing will happen. However, when you touch it with enough force to make it fall over, you have reached the threshold. Once you met the threshold all of the dominos will fall, not just the first one.
Polarized refers to the state that the neuron is in when it is resting or not being stimulated. Depolarization occurs when the threshold has been reached and the ions are being exchanged across the membrane. This is called an action potential and is equivalent to the time when the dominos are falling. Repolarization is the return of the neuron to its resting state. The refractory period is the amount of time it takes before the nerve cell can be restimulated. If the dominos fall over, you cannot knock them over again until they are reset, the amount of time needed to reset is called the refractory period. Sometimes during polarization, the cell overshoots how many ions it is suppossed to put out and that is called hyperpolarization.
