By definition, the refractory period is a period of time during which a cell is incapable of repeating an action potential. In terms of action potentials, it refers to the amount of time it takes for an excitable membrane to be ready to respond to a second stimulus once it returns to a resting state.
What is 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 relative and absolute refractory period?
Absolute: Is the period of time during which a second action potential ABSOLUTELY cannot be initiated, no matter how large the applied stimulus is. Relative: Is the interval immediately following the Absolute Refractory Period during which initiation of a second action potential is INHIBITED, but not impossible.
Do action potentials have a refractory period?
In its wake, the action potential leaves the Na+ channels inactivated and K+ channels activated for a brief time. These transitory changes make it harder for the axon to produce subsequent action potentials during this interval, which is called the refractory period.
Why is it called relative refractory period?
The cell membrane cannot immediately produce a second AP. 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.
What is the 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.
Where does relative refractory period occur?
The relative refractory period is the period that occurs during the undershoot phase; where an action potential can be activated but only if the trigger (stimulus) is large enough.
Which statement best describes the relative refractory period?
Which of the following statements correctly describes the relative refractory period? It is the period in which even a weak impulse can cause another depolarization.
During what phase S of the action potential does the relative refractory period overlap?
The relative refractory period refers to that time during which a stronger stimulus will lead to the generation of a new action potential. The relative refractory period coincides with the hyperpolarization phase of the action potential.
What is a refractory period biology?
(neurology) the time after a neuron fires or a muscle fiber contracts during which a stimulus will not evoke a response.
What causes absolute and relative refractory period?
The relative refractory period is the interval of time during which a second action potential can be initiated, but initiation will require a greater stimulus than before. Refractory periods are caused by the inactivation gate of the Na+ channel.
Which phase is the refractory period?
For the first millisecond or so after phase 1 the voltage-gated sodium channels are still inactive, which means that they will not open in response to depolarization. This is called the absolute refractory period, and it is impossible to evoke another action potential in this period.
What is an example of a refractory period?
An example of the refractory period is when talking on the phone while driving causes you to react slower to seeing a stopped car in front of you. So the next time you see a friend texting and driving, remind them that by doing so they are slowing their reaction time, which could be dangerous.
What is the refractory period quizlet?
Refractory Period. The time period from the beginning of the action potential to the return to resting state during which the membrane will not respond normally to additional stimuli.
What is an action potential?
The action potential is an explosion of electrical activity that is created by a depolarizing current. This means that some event (a stimulus) causes the resting potential to move toward 0 mV. When the depolarization reaches about -55 mV a neuron will fire an action potential. This is the threshold.
Why is it harder to generate a second action potential during the relative refractory period?
4. Why is it harder to generate a second action potential during the relative refractory period? A greater stimulus is required because voltage-gated potassium channels that oppose depolarization are open during this time.