What happens during absolute refractory period?

Asked By: Qiuyun Ploigt | Last Updated: 15th April, 2020
Category: medical health brain and nervous system disorders
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During the absolute refractory period, the neuron cannot be excited to generate a second action potential (no matter how intense the stimulus). This recovery period is the relative refractory period during which a stronger than normal stimulus is needed to initiate a new action potential.

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Similarly, you may ask, what is the purpose of the absolute refractory period?

The absolute refractory period refers to a period during the action potential. This is the time during which another stimulus given to the neuron (no matter how strong) will not lead to a second action potential.

Also Know, what occurs during the refractory period quizlet? a brief time period after an action potential has been initiated during which an axon is either incapable of generating another action potential. The excitable plasma membrane recovers at this time and becomes ready to respond to another stimulus.

Regarding this, what is the relative refractory period?

Medical Definition of relative refractory period : the period shortly after the firing of a nerve fiber when partial repolarization has occurred and a greater than normal stimulus can stimulate a second response — compare absolute refractory period.

What is the relative refractory period caused by?

As voltage-gated Na+ channels transition from the inactivated to the closed state (i.e., they become capable of being activated), the membrane becomes capable of supporting a 2nd action potential - this period is called the RELATIVE REFRACTORY PERIOD.

32 Related Question Answers Found

Why do males have a refractory period?

An increased infusion of the hormone oxytocin during ejaculation is believed to be chiefly responsible for the male refractory period, and the amount by which oxytocin is increased may affect the length of each refractory period.

At what point does the absolute refractory period begin?

This is the time during which another stimulus given to the neuron (no matter how strong) will not lead to a second action potential. Thus, because Na+ channels are inactivated during this time, additional depolarizing stimuli do not lead to new action potentials. The absolute refractory period takes about 1-2 ms.

What is the molecular basis of the absolute refractory period?

The absolute refractory period is the time during which another stimulus given to the cell (no matter how strong) will not lead to a second action potential. The molecular basis of the absolute refractory period is described by the ball-and-chain model.

What occurs during the refractory period psychology?

The Refractory Period Defined
In other words, presenting two stimuli close together causes a person to respond slower to the second stimuli than he or she normally would. Researchers believe that the refractory period occurs because a person must process the first stimulus before the second can be dealt with.

What happens during hyperpolarization?

Hyperpolarization is a change in a cell's membrane potential that makes it more negative. It is the opposite of a depolarization. It inhibits action potentials by increasing the stimulus required to move the membrane potential to the action potential threshold.

Why does cardiac muscle have long refractory period?

It is important for the cardiac muscle cells to have a longer refractory period because if they were short, the heart could enter tetanic contraction/summation which is when the muscle is stimulated so rapidly that it does not have a chance to relax at all between stimuli.

Why is the resting membrane potential negatively charged?

When the neuronal membrane is at rest, the resting potential is negative due to the accumulation of more sodium ions outside the cell than potassium ions inside the cell.

What is the absolute refractory period quizlet?

absolute refractory period (neuron) The interval from the beginning of the action potential until the nerve fiber is able to conduct another action potential; during most of this interval the Na+ and K+ channels remain open. You just studied 6 terms!

What does depolarization mean?

In biology, depolarization is a change within a cell, during which the cell undergoes a shift in electric charge distribution, resulting in less negative charge inside the cell. Depolarization is essential to the function of many cells, communication between cells, and the overall physiology of an organism.

What is the absolute refractory period of cardiac muscle?

The absolute refractory period of the cardiac muscle action potential refers to the time interval when the voltage gated sodium channels are inactivated. The absolute refractory period lasts ~180 msec. The action potential lasts 200-220 msec.

What is Saltatory conduction?

Saltatory conduction (from the Latin saltare, to hop or leap) is the propagation of action potentials along myelinated axons from one node of Ranvier to the next node, increasing the conduction velocity of action potentials.

What is relative refractory period quizlet?

Relative Refractory Period. Period in which the threshold for an action potential (AP) generation is elevated. Relative Refractory Period. Period in which ONLY exceptionally STRONG stimulus could stimulate an action potential (AP) Returned, Resting State, Open, Repolarization.

What is the all or none response?

The all-or-none law is a principle that states that the strength of a response of a nerve cell or muscle fiber is not dependent upon the strength of the stimulus.

How is threshold reached?

An action potential occurs when a neuron sends information down an axon, away from the cell body. When the depolarization reaches about -55 mV a neuron will fire an action potential. This is the threshold. If the neuron does not reach this critical threshold level, then no action potential will fire.

Why is action potential unidirectional?

Action potential propagation in axons
Unlike graded potentials, the propogation of an action potential is unidirectional, because the absolute refractory period prevents the initiation of an AP in a region of membrane that has just produced an AP.

How does repolarization occur?

Repolarization is a stage of an action potential in which the cell experiences a decrease of voltage due to the efflux of potassium (K+) ions along its electrochemical gradient. This phase occurs after the cell reaches its highest voltage from depolarization.

During which period can a second action potential be initiated by a larger than normal stimulus?

Refractory periods
The relative refractory period is the interval in which a second action potential can be generated, but only with a stronger stimulus than usual. The absolute refractory period is due to inactivation of the voltage-gated sodium channels (Fig. 6.11).