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How fast does an action potential travel down a myelinated nerve?
Wiki User
∙ 15y ago
An action potential is not passively propagated down the axon. There have to be ion channels along the axon or else the action potential will gradually decay. So the the rate of that the action potential 'travels' is dependent on the passive property called the length constant of the axon (factor in capacitance, axon diameter) plus the density of ion channels.
Wiki User
∙ 15y ago
Wiki User
∙ 13y ago50 m/sec
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In which direction does a nerve impulse usually move?
It's called the ACTION POTENTIAL, or, in the case of a myelinated axon, SALTATORY CONDUCTION.
The speed of nerve impulse transmission through the axon of a sensory neuron will be quickest in?
I'm guessing; "myelinated nerve fibres" contrary to the much slower "non-myelinated nerve fibres"
Why is action potential self regenerating?
By self regenerating, they mean that when you start an action potential, it continues in proximal (nearby) tissue (e.g., nerve). The depolarization of the action potential continues along the nerve.
Would conduction speed of a nerve fiber be the fastest in a large or small myelinated fiber?
Yes. Myelinated fibers have a myelin sheath around them which keeps the impulse from scattering and on a direct path. This makes the impulse travel faster than unmyelinated fibers.
What does a conduction velocity of an action potential depend on?
An action potential does not have a conduction velocity. Rather, it makes sense to measure the conduction velocity of nerves or nerve cells and this is usually done in metres per second (m/s.). An action potential is characterised as "an all or none response". This means you cannot alter the characteristics of an action potential in a given nerve cell. If you get a nerve cell and manage to get it to threshold, produce and measure an action potential 1000 times or more at the exact same point on the cell, the action potential you measure will not change in timing or amplitude. Information travels down a nerve cell through action potentials. But it is not one action potential that travels the whole length of the axon. Instead what happens is that one action potential causes the next bit of the nerve cell to reach threshold and therefore creates an entirely new action potential. So you actually need multiple action potentials to happen along a nerve cell to send information down it. We call this "propagation of action potentials" since each action potential produces a new one. More properly, it is referred to as "saltatory action potential conduction". Conduction velocity is basically a measure of how quickly we can produce a series of action potentials to travel the distance of the nerve cell axon. Since action potentials only happen at each "Node of Ranvier", then the longer the distance between each node (internodal distance), the faster the conduction velocity of a nerve cell. Since the internodal distance is positively correlated with myelin thickness, more thickly myelinated nerve cells have faster conduction velocities. The thickest and fastest nerve cells are motor neurones and Ia fibres from muscle spindles with a diameter of 12-20 micrometres and a conduction velocity of 70-120 m/s. The thinnest/slowest are fibres used to convey slow pain (<1.5 micrometres and 0.5-2 m/s).
In which direction does a nerve impulse usually move?
It's called the ACTION POTENTIAL, or, in the case of a myelinated axon, SALTATORY CONDUCTION.
How is nerve impulse conducted along a myelinated nerve fiber?
In non-myelinated axons, the nerve impulse is going to be produced when the action potential accross a membrane makes a wave of depolarization followed by a wave of repolarization. With the absence of the myelin, the impulse is transmitted continuously throughout the membrane. In a non-myelinated nerve, once an end of the cell, the dendrite, is depolarized, the depolarization a.k.a., the action potential, moves along the nerve membrane, and the area of membrane immediately behind the depolarized section becomes repolarized.
An electrical impulse moving down an axon is called?
This is called action potential. Action potential is the change in electrical potential that occurs between the inside and outside of a nerve or muscle fiber when it is stimulated, serving to transmit nerve signals.
Is an action potential necessary for a nerve impulse to occur?
Yes, an action potential is needed for a nerve impulse to occur.
Is a action potential necessary for a nerve impulse to occur?
Yes, an action potential is needed for a nerve impulse to occur.
What are the advantages of the refractory period?
Ensure nerve impulses travel in one direction and limit the number of action potential
The speed of nerve impulse transmission through the axon of a sensory neuron will be quickest in?
I'm guessing; "myelinated nerve fibres" contrary to the much slower "non-myelinated nerve fibres"
Also called a nerve impulse transmitted by axons?
action potential
Why is action potential self-regenerating?
By self regenerating, they mean that when you start an action potential, it continues in proximal (nearby) tissue (e.g., nerve). The depolarization of the action potential continues along the nerve.
Why is action potential self regenerating?
By self regenerating, they mean that when you start an action potential, it continues in proximal (nearby) tissue (e.g., nerve). The depolarization of the action potential continues along the nerve.
Would conduction speed of a nerve fiber be the fastest in a large or small myelinated fiber?
Yes. Myelinated fibers have a myelin sheath around them which keeps the impulse from scattering and on a direct path. This makes the impulse travel faster than unmyelinated fibers.
What does a conduction velocity of an action potential depend on?
An action potential does not have a conduction velocity. Rather, it makes sense to measure the conduction velocity of nerves or nerve cells and this is usually done in metres per second (m/s.). An action potential is characterised as "an all or none response". This means you cannot alter the characteristics of an action potential in a given nerve cell. If you get a nerve cell and manage to get it to threshold, produce and measure an action potential 1000 times or more at the exact same point on the cell, the action potential you measure will not change in timing or amplitude. Information travels down a nerve cell through action potentials. But it is not one action potential that travels the whole length of the axon. Instead what happens is that one action potential causes the next bit of the nerve cell to reach threshold and therefore creates an entirely new action potential. So you actually need multiple action potentials to happen along a nerve cell to send information down it. We call this "propagation of action potentials" since each action potential produces a new one. More properly, it is referred to as "saltatory action potential conduction". Conduction velocity is basically a measure of how quickly we can produce a series of action potentials to travel the distance of the nerve cell axon. Since action potentials only happen at each "Node of Ranvier", then the longer the distance between each node (internodal distance), the faster the conduction velocity of a nerve cell. Since the internodal distance is positively correlated with myelin thickness, more thickly myelinated nerve cells have faster conduction velocities. The thickest and fastest nerve cells are motor neurones and Ia fibres from muscle spindles with a diameter of 12-20 micrometres and a conduction velocity of 70-120 m/s. The thinnest/slowest are fibres used to convey slow pain (<1.5 micrometres and 0.5-2 m/s).
