Does length of nerve affect nerve conduction velocity?

Nerve conduction velocity depends critically on axon diameter and myelination (Arbuthnott et al., 1980). (1977) predicted in their theoretical model that at long internodal lengths (such as found in large mammal and human peripheral nerve), nerve conduction velocity would become less dependent on the internodal length.

What affects nerve impulse velocity?

The presence of a myelin sheath increases the speed of conduction of nerve impulses. Myelinated axons conduct impulses about 10 times faster than comparable unmyelinated ones. The sheath insulates the axon and covers up the section beneath it.

Does length of axon affect conduction velocity?

Chomiak et al. showed that conduction velocity in the minor axon branches, connecting the ipsilateral targets, is related to the axonal length from the origin neuron (Chomiak et al., 2008). Conduction velocity is decreased in shorter axons, and vice versa, to allow isochronic spiking at the target nuclei.

What is the relationship between the speed of a nerve impulse and the size of the axon?

Variation in axon size is important because the speed of conduction along an axon is partially dependant on the size of the axon. Generally, the fatter the axon, the faster a nerve impulse travels.

What does conduction velocity depend on?

Conduction velocity is dependent on internode distance, with a broad maximum centered around the value observed in normal peripheral fibers. Conduction velocity is also dependent on temperature and the properties of the axonal milieu.

What increases nerve conduction velocity?

Temperature. In general, the conduction velocities of most motor and sensory nerves are positively and linearly associated with body temperature (low temperatures slow nerve conduction velocity and higher temperatures increase conduction velocity).

How does a nerve impulse travel through a neuron?

Neurotransmitters travel across the synapse between the axon and the dendrite of the next neuron. Neurotransmitters bind to the membrane of the dendrite. The binding allows the nerve impulse to travel through the receiving neuron.

What determines action potential conduction velocity?

The conduction velocity of the action potential is determined by measuring the distance traveled (length of the nerve in m) and dividing by the time (sec) taken to complete the reflex arc, also called the latency. Conduction velocity = distance (m)/time (sec).

What increases action potential conduction velocity?

myelination
As a general rule, myelination increases the conduction velocity of action potentials and makes them more energy-efficient. Whether saltatory or not, the mean conduction velocity of an action potential ranges from 1 meter per second (m/s) to over 100 m/s, and, in general, increases with axonal diameter.

What happens to the length constant if we decrease the membrane resistance?

What happens to the length constant if we decrease the membrane resistance? Again, we can use the expression for the length constant to understand this question. Axial resistance is in the denominator of the equation, and so a decrease in axial resistance will also lead to an increase in the length constant.

Which of the following would result in an increase in conduction velocity of an impulse through the heart?

Sympathetic activation
Sympathetic activation increases conduction velocity in the AV node by increasing the rate of depolarization (increasing slope of phase 0) of the action potentials. This leads to more rapid depolarization of adjacent cells, which leads to a more rapid conduction of action potentials (positive dromotropy).