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Why do not action potentials occur during the repolarization phase?
Wiki User
∙ 12y ago
It has to do with what types of channels are open during this phase. In the repolarization phase the number of potassium channels are increased and the number of sodium channels are decreased. This allows for action potentials to not occur. Otherwise, the action potentials would add up and produce tetany.
Wiki User
∙ 12y ago
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What is the stage in an action potential that immediately follow depolarisation?
After depolarization repolarization occur whcih then again lead to resting potentiol
Does action potentials occur at nodes?
yes, the action potential occurs at the nodes of Ranvier -- there are Na (sodium channels) there that are depolarized/opened to maintain the action potential.
What changes occur in the neuron?
Neurons undergo depolarization and repolarization when stimulated. The sodium and potassium channels open.
What is the process called when sodium NA is pumped out of a nerve cell?
during action potentials, sodium and potassium cross the membrane of the synapse after the threshold of membrane potential is reached. There, sodium leaves the synapse and the membrane potential is now positive. this is known as depolarization. then during repolarization, the sodium channels close and the potassium channels open to stabilize the membrane potential. during this time, a second action potential cannot occur and this is an evolutionary advantage because it allows rest in the nerve cells and it allows the membrane potential to equalize.
Where do action potentials occur?
The spike initiation zone, also called axon hillock, is the point where the cell body of the neuron meets the axon and is the point where most action potentials are initiated.
What is the stage in an action potential that immediately follow depolarisation?
After depolarization repolarization occur whcih then again lead to resting potentiol
What are the events that must occur to generate action potential?
Local polarization is the first step. Next the generation and propagation of an action potential. Lastly repolarization has to take place.
Does action potentials occur at nodes?
yes, the action potential occurs at the nodes of Ranvier -- there are Na (sodium channels) there that are depolarized/opened to maintain the action potential.
Before a muscle cell can be stimulated to contract again what must occur?
Repolarization
What is the result of parasympathetic stimulation of the SA node?
Action potentials will occur less often due to an increase in the membranes permeability to K+
What part of the ear converts vibrations to action potentials?
The inner ear contains the receptors for sound which convert fluid motion into action potentials that are sent to the brain to enable sound perception. The airborne sound waves must be transferred into the inner ear for hearing to occur.
Where do graded potentials occur?
On the dendrites and subsequently the soma (body) of neurons.
What changes occur in the neuron?
Neurons undergo depolarization and repolarization when stimulated. The sodium and potassium channels open.
What is the process called when sodium NA is pumped out of a nerve cell?
during action potentials, sodium and potassium cross the membrane of the synapse after the threshold of membrane potential is reached. There, sodium leaves the synapse and the membrane potential is now positive. this is known as depolarization. then during repolarization, the sodium channels close and the potassium channels open to stabilize the membrane potential. during this time, a second action potential cannot occur and this is an evolutionary advantage because it allows rest in the nerve cells and it allows the membrane potential to equalize.
Where do action potentials occur?
The spike initiation zone, also called axon hillock, is the point where the cell body of the neuron meets the axon and is the point where most action potentials are initiated.
What can occur when the effects of one graded potential are added onto the effects produced by another graded potential which can lead to an action potential.?
More sodium ions pile up (accumulate) at the axon hillock from the combination of the two (or more) graded potentials, which may be then be sufficient to initiate the action potential.
What can occur when the effects of one graded potential are added onto the effects produced by another graded potential which can lead to an action potential?
More sodium ions pile up (accumulate) at the axon hillock from the combination of the two (or more) graded potentials, which may be then be sufficient to initiate the action potential.
