Neuron Action Potential 2

Topic: Physiology

Created on Monday, September 1 2014 by jdmiles

Last modified on Monday, September 1 2014.

 
        A) A neuron can fire over 1,000 action potentials per second
 
        B) An action potential is only able to propagate over a short distance, determined by the length constant
 
        C) It is a self-propagating wave of hyperpolarization
 
        D) Action potentials vary in amplitude from one to the next
 
        E) It does not significantly change in amplitude from the proximal end of the axon to the distal end
 

 

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This question was created on September 01, 2014 by jdmiles.
This question was last modified on September 01, 2014.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

ANSWERS AND EXPLANATIONS

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A) A neuron can fire over 1,000 action potentials per second

This answer is incorrect.

Action potentials are self-propagating waves of depolarization that travel the entire length of an axon without significantly changing in amplitude. Since they are all-or-none events, the peak amplitude of an action potential does not significantly change form one action potential to the next. The axon membrane needs some time to recover after each action potential, so there is a finite rate at which they can occur. The absolute maximum rate of action potential firing is about 1000 per second, but most neurons have maximum firing rates that are much slower than that.  (See References)

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B) An action potential is only able to propagate over a short distance, determined by the length constant

This answer is incorrect.

Action potentials are self-propagating waves of depolarization that travel the entire length of an axon without significantly changing in amplitude. Since they are all-or-none events, the peak amplitude of an action potential does not significantly change form one action potential to the next. The axon membrane needs some time to recover after each action potential, so there is a finite rate at which they can occur. The absolute maximum rate of action potential firing is about 1000 per second, but most neurons have maximum firing rates that are much slower than that.  (See References)

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C) It is a self-propagating wave of hyperpolarization

This answer is incorrect.

Action potentials are self-propagating waves of depolarization that travel the entire length of an axon without significantly changing in amplitude. Since they are all-or-none events, the peak amplitude of an action potential does not significantly change form one action potential to the next. The axon membrane needs some time to recover after each action potential, so there is a finite rate at which they can occur. The absolute maximum rate of action potential firing is about 1000 per second, but most neurons have maximum firing rates that are much slower than that.  (See References)

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D) Action potentials vary in amplitude from one to the next

This answer is incorrect.

Action potentials are self-propagating waves of depolarization that travel the entire length of an axon without significantly changing in amplitude. Since they are all-or-none events, the peak amplitude of an action potential does not significantly change form one action potential to the next. The axon membrane needs some time to recover after each action potential, so there is a finite rate at which they can occur. The absolute maximum rate of action potential firing is about 1000 per second, but most neurons have maximum firing rates that are much slower than that.  (See References)

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---

E) It does not significantly change in amplitude from the proximal end of the axon to the distal end

This answer is correct.

Action potentials are self-propagating waves of depolarization that travel the entire length of an axon without significantly changing in amplitude. Since they are all-or-none events, the peak amplitude of an action potential does not significantly change form one action potential to the next. The axon membrane needs some time to recover after each action potential, so there is a finite rate at which they can occur. The absolute maximum rate of action potential firing is about 1000 per second, but most neurons have maximum firing rates that are much slower than that.  (See References)

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References:

1. John Nolte; three-dimentional brain reconstructions by John Sundsten. The human brain: an introduction to its functional anatomy. Philadelphia, PA : Mosby/Elsevier, c2009. (ISBN:0323041310)

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physiology
Neuron Action Potential 2
Question ID: 90114167
Question written by J. Douglas Miles, (C) 2006-2009, all rights reserved.
Created: 09/01/2014
Modified: 09/01/2014
Estimated Permutations: 360