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Whether the nerve fiber is myelinated or unmyelinated effects speed of a nerve impulse.
A myelinated nerve impulse is faster.
Also the diameter of the nerve fiber effects nerve impulse speed.
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∙ 13y ago
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∙ 7y agoThe speed of light in the vacuum is always the same - there is nothing that affects it.If light travels within a substance, the speed of light in that substance depends on the properties of the specific substance. It also depends on the frequency of light, i.e., different frequencies may have somewhat different speeds.
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∙ 7y agoHere are the factors which affect the propagation of an action potential:
1. Refractory periodDuring the absolute refractory period, a second action potential cannot be generated as the Na+ gates are inactivated. As for the relative refractory period, a second action potential can only be generated with a strong stimulus as some Na+ gates are still inactivated. This results in the action potential traveling in a unidirectional manner.
2. Axon diameter
The larger the fiber, the less resistance there is to the local current flow. The impulse can hence be conducted more quickly. Smaller fibers have more resistance so the impulse travels more slowly.
3. Myelination
Saltatory conduction is possible in myelinated axons. During saltatory conduction, the action potential is only generated at the myelin sheath gaps and the electric signal can jump rapidly from gap to gap. This allows the impulse to travel 30 times faster than in unmyelinated axons.
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∙ 9y agoThe speed of sound is affected by the medium air, water, or metal and the temperature, but not the air pressure.
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∙ 13y agothe presence or absence of a myelin sheath
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∙ 13y agoFriction. The greater the friction the slower the Velocity...therefore you nned to be able to move the object or object easily ro gain higher velocity. Take a physics course.
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∙ 9y agoDistance and time are the two factors that speed depends on. The definition of Speed is change in Distance per change in time. S=D/t.
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∙ 13y agomyelination, which is due to oligodendrocytes or schwann cells and the stimulation
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∙ 7y agoThe refractive index of the medium through which it is travelling and, unless it is through vacuum, the frequency or wavelength of the light.
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∙ 13y agomylenin sheath and axon diamter
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COnduction speed of a nerve fiber would be the fastest in a?
...in a myelinated axon.
1 List the physiological events that occur between delivery of the stimulus and the start of the recorded response?
The speed of nerve impulse transmission changes as the body ages. In infants, the transmission speed is only about half that seen in adults. By age five, most people have attained the adult velocity. A gradual decline in conduction velocity begins as people reach their 20s, and continues for the remainder of life. Another factor that influences conduction velocity is the length of the nerve itself. An impulse that has to travel a longer distance will take longer. Some nerves are naturally longer than others. Measurement of nerve conduction takes into account the length of the target nerve. Some other factors are: · Initiation of action potential in nerve fibers; · Conduction of impulse; · Release of acetylcholine from the nerve terminals; · Binding of acetylcholine to receptors of the motor end plate; · Depolarization of the end plate; · Initiation of action potential in muscle fibers; · Muscle contraction.
How does myelination affect nerve conduction velocity?
Myelination will speed the nerve conduction velocity considerably. Myelin is found in Schwann cells which encircle a given axon. It acts mainly as an insulator so that depolarization in one cell does not set off depolarizations in adjoining cells. When a neural membrane is depolarized, local currents are set up between positive and negative ions causing membrane conduction. In myelinated fibers, the local currents go from one internode (or node of Ranvier) in between two Schwann cells to the next internode. Thus we have "salutatory conduction" where a neural impulse actually jumps from one internode to the next without being conducted down the entire cell membrane.
Nodes of ranvier are found in?
In invertebrate nerves, axons and dendrites are uncovered, and signal transfer is a fairly slow process. In vertebrates, many axons and dendrites are covered in myelin, a fatty substance which insulates the nerves and speeds up conduction. However, for signal conduction to occur, ions have to be able to move in and out of the nerve along its length to transmit the impulse. Since ions can't diffuse through myelin, they have to go through the nodes of Ranvier. This is called saltatory conduct.
How fast can nerve signals travel?
Nerve signals travel at a speed of 0.5-150 m/s. The speed varies greatly depending on how much myelin there is around the nerve thread, more myelin means higher speeds.
What do nerve conduction velocity studies?
Nerve conduction velocity studies (NCV) are used to measure the speed with which an electrical signal is transferred along the nerve.
What is electroneurography?
The measurement of the speed of conduction of impulses down a peripheral nerve.
COnduction speed of a nerve fiber would be the fastest in a?
...in a myelinated axon.
What is Nerve conduction testing?
Procedure that measures the speed at which impulses move through the nerves.
What is the effect of the myelin sheath on synaptic transmission?
Myalin sheath gives insulation to the neurons. They also hasten the nerve conduction by saltatory conduction.
What is involved in electromyographic and nerve conduction velocity testing?
These tests involve stimulating the median nerve with electricity and measuring the resulting speed and strength of the muscle response, as well as recording speed of nerve transmission across the carpal tunnel.
What is the myelin sheath's function?
The function of the myelin sheath is to insulate the axon of the neuron. When there are gaps in the sheath, known as nodes of Ranvier, the nerve impulse can jump from gap to gap, thus increasing greatly the speed of conduction of the nerve impulse. This is known as saltatory conduction.
What the function of the myelin sheath?
The function of the myelin sheath is to insulate the axon of the neuron. When there are gaps in the sheath, known as nodes of Ranvier, the nerve impulse can jump from gap to gap, thus increasing greatly the speed of conduction of the nerve impulse. This is known as saltatory conduction.
1 List the physiological events that occur between delivery of the stimulus and the start of the recorded response?
The speed of nerve impulse transmission changes as the body ages. In infants, the transmission speed is only about half that seen in adults. By age five, most people have attained the adult velocity. A gradual decline in conduction velocity begins as people reach their 20s, and continues for the remainder of life. Another factor that influences conduction velocity is the length of the nerve itself. An impulse that has to travel a longer distance will take longer. Some nerves are naturally longer than others. Measurement of nerve conduction takes into account the length of the target nerve. Some other factors are: · Initiation of action potential in nerve fibers; · Conduction of impulse; · Release of acetylcholine from the nerve terminals; · Binding of acetylcholine to receptors of the motor end plate; · Depolarization of the end plate; · Initiation of action potential in muscle fibers; · Muscle contraction.
What are the factors which affect the nerve conduction velocity?
The factors affecting nerve conduction velocity are as follows:(i) Axon diameter:An axon with a larger diameter conducts faster. In an unmyelinated fiber, the speed of propagation is directly proportional to the square root of the fiber diameter (D), i.e.,Conduction velocity a D(ii) Myelination and saltatory conduction:Myelination speeds up conduction. Thus, the action potential travels electrotonically along the long myelinated segments, and fresh action potentials are generated only at the nodes. This is called saltatory conduction. In a myelinated neuron, the conduction velocity is directly proportional to the fiber diameter (D).(iii) Temperature:A decrease in temperature slows down conduction velocity, (iv) Resting membrane potential. Effect of RMP changes on conduction velocity is quite variable. Usually, any change in the RMP in either direction (hyper polarization or depolarization) slows down the conduction velocity.
How to calculate the speed of propagation of the nerve impulse in a nerve fiber?
The velocity of nerve conduction is usually assessed by dissecting out a nerve fiber from an animal such as a frog. The nerve is placed in a chamber containing stimulating and recording electrodes. The responses of the nerve can be monitored using an oscilloscope. More detail on this procedure can be found in the related link.
How does temperature on a physiological way effect nerve conduction?
Myelination will speed the nerve conduction velocity considerably. Myelin is found in Schwann cells which encircle a given axon. It acts mainly as an insulator so that depolarization in one cell does not set off depolarizations in adjoining cells. When a neural membrane is depolarized, local currents are set up between positive and negative ions causing membrane conduction. In myelinated fibers, the local currents go from one internode (or node of Ranvier) in between two Schwann cells to the next internode. Thus we have "salutatory conduction" where a neural impulse actually jumps from one internode to the next without being conducted down the entire cell membrane.
