The refractory period generally lasts one millisecond
Absolute refactory period
The absolute refractory period. This period occurs after the action potential has been initiated and is a result of inactivation of the sodium channels. These sodium channels would normally open up to allow sodium influx into the cell during an action potential. The absolute refractory period occurs during an ongoing action potential and is the period in which a subsequent action potential absolutely cannot be generated.This should not be confused with the relative refractory period which occurs immediately following the absolute refractory period (during membrane hyperpolarization). During this period a subsequent action potential is possible, but more difficult to attain.
THe absolute refractory period
Repolarization
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Absolute refactory period
The cardiac muscle fiber absolute refractory is a long period of time (longer then skeletal muscles), so you cannot tetanize cardiac muscle fibers because it has to relax before it is able to contract again.
refractory period is the interval between action potential , the absolute refractory period is the period in which second action potential can not be initiated but in relative refractory period the second action potential can be initiated by the more strong stimulus.
After the generation and propagation of an action potential along a neuron, the cell becomes depolarized to the point where there is no potential for further signaling until the cell re-polarizes through the action of ion pumps. This very brief period is called the refractory state.
The absolute refractory period coincides with pretty much the entire duration of the action potential. It is caused by the inactivation in neurons.
Muscle tetany occurs in muscles without absolute refractory period. The stimulus for contraction comes before the preceding contraction/relaxation is over leading to multiple action potentials without a refractory period. It does not occur in cardiac muscle because it has absolute refractory period during which the muscle cannot be excited, thus making tetany impossible
Absolute Refractory Period:It is the interval during which a second action potential absolutely cannot be initiated, no matter how large a stimulus is applied.ORAfter repolarization there is a period during which a second action potential cannot be initiated, no matter how large a stimulus current is applied to the neuron. This is called the absolute refractory period, and it is followed by a relative refractory period, during which another action potential can be generated
The absolute refractory period. This period occurs after the action potential has been initiated and is a result of inactivation of the sodium channels. These sodium channels would normally open up to allow sodium influx into the cell during an action potential. The absolute refractory period occurs during an ongoing action potential and is the period in which a subsequent action potential absolutely cannot be generated.This should not be confused with the relative refractory period which occurs immediately following the absolute refractory period (during membrane hyperpolarization). During this period a subsequent action potential is possible, but more difficult to attain.
In absolute refractory period, none of channels are reconfigured, so that second active potential cannot be generated no matter how large the stimulus current is applied to the neuron. In contrast, in relative refractory period, some but not all of channels are reconfigured, another action potential can be generated but only by a greater stimulus current thatn that originally needed.
tetanic contractions might occur, which would stop the hearts pumping action
THe absolute refractory period
Absolute refractory period