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The generation of a second action in some neurons can only happen after a refractory period, when the membrane potential has returned it's base level or even more negative. This is because some types of Na+ channels inactivate at a positive potential and then require a negative potential to reset. Other neurons have other types of channels and can fire multiple action potentials to a single depolarization.
Wiki User
∙ 13y ago
Wiki User
∙ 11y agoThe absolute refractory period is the period after an action potential when initiation of a second action potential is impossible. This is due to an initial inactivation of Na+ channels after the peak of the action potential is obtained because the initiation of an action potential requires influx of Na+. A new action potential cannot be obtained until the voltage gated sodium channels close and become active again.
There is also a relative refractory period between stimuli when an action potential can be obtained, but the threshold to initiate that action potential is raised. This is probably due to delayed closing of the K channels.
Wiki User
∙ 12y agothe membrane potential has been reestablished
Wiki User
∙ 11y agorest potential
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How are neural impulses generated?
The neural impulse is the electrical charge that goes from the nerve receptor to the brain. They are generated when the nerve receptor detects a foreign stimuli.
Where does a nerve impulse start?
A nerve impulse starts at the dendrite
The duration of a nerve impulse is approximately?
A nerve impulse is approximately 1 millisecond.
The events of a nerve impulse?
The electrical impulse in a nerve cell begins when ions move through the cells surface through ion channels.The nerve impulse.A nerve impulse is a wave of excitation that quickly travels within the surface of a neurone (nerve cell). This nerve impulse usually travels on certain parts of the nerve cell: on a dendrite or an axon. Within a neurone the first event depends on the type of 'nerve impulse'; there are two important types:1- nerve impulses generated at dendrites2- self propagating nerve impulses (action potentials) that travel along the axonNerve impulses generated at dendrites.Dendrites feed into the 'cell body' (soma) of a neurone. Nerve impulses that are generated in these dendrites travel toward the cell body.A sequence of events occur at the surface of a dendrite when the nerve impulse is sparked. The first event is transduction; this involves the transformation of one form of energy outside the dendrite into electrical energy within the dendrite.Nerve impulses that travel along axons.Nerve cells often have many dendrites but often only have a single axon. The essential difference between the two parts of the nerve cell is:- in dendrites electrical impulses travel TOWARDS the cell body of the neurone- in the axon the electrical impulses travel AWAY from the cell body of the neuroneThe nerve impulse that travels along an axon begins at the 'base of the axon', where the cell body and axon merge. This site is called the 'axon hillock' and is found to be the site where the first event in the formation of a nerve impulse actually occurs. Again, the first event is transduction at the axon hillock.Conclusion; the first event.For both of the cases above, and for virtually any other case, the nerve impulse begins with a process of transduction. The electrical nerve impulse begins once the first 'ions' leave or enter the nerve cell. Usually sodium ions enter, sometimes calcium ions are the firs to enter, sometimes potassium ions are the first to leave.
How is the Nerve impulse responsible for the pupil becoming smaller?
Pupil is a window for the light to enter our eyes. When we are in a dim light a nerve impulse is generated to the brain to enlarge the pupil. Size of pupil is managed by the iris (coloured part of the eye). If excessive light is there, the pupil shrinks to a smaller size so that the eye's not damaged esp. the retina where the image of objects are formed
How are neural impulses generated?
The neural impulse is the electrical charge that goes from the nerve receptor to the brain. They are generated when the nerve receptor detects a foreign stimuli.
What is impulse in the nervous system?
electrical wave conducted along the nerve generated by the voltage difference across the cell membrane of the nerve cells.
How fast does a nerve impulse travels?
It 200 miles per hour And it can probally be in meters too.
Which membrane potential results in depolarization without a nerve impulse being generated?
excitatory postsynaptic potential
Which membrane potential results in depolorization without a nerve impulse being generated?
excitatory postsynaptic potential
How can a nerve impulse travel?
100 meters per second
Why can a nerve still be alive when a person is dead?
A nerve is simply a line of cells through which electrical impulses travel. These electrical impulses are generated by the movement of Sodium and potassium ions into and out of the cells which generates an action potential (impulse). Nerve cells can be stimulated once a person is dead if an electrical impulse is generated and so appear to be alive.
What is quicker a nerve impulse or a hormone?
nerve impulse
Where does a nerve impulse start?
A nerve impulse starts at the dendrite
Which travels quicker through the body a nerve impulse or a hormons?
a nerve impulse
The neurotransmitters of a neutron enable a nerve impulse to do what?
they transport the nerve impulse through the synapses (:
Is ventricular systole responsible for nerve impulse?
no ventricular diastole is responsible for nerve impulse
