nerve impulse


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impulse

 [im´puls]
1. a sudden pushing force.
2. a sudden uncontrollable determination to act.
cardiac impulse a heartbeat palpated over the left side of the chest at the apex of the heart. See also point of maximal impulse.
impulse control disorders a group of mental disorders characterized by repeated failure to resist an impulse to perform some act harmful to oneself or to others. In spite of the act's being socially unacceptable or inconsistent with the rest of the person's personality or lifestyle, he or she feels pleasure or emotional release upon doing it. Disorders in this category include intermittent explosive disorder, kleptomania, pathological gambling, pyromania, and trichotillomania.
nerve impulse the electrochemical process propagated along nerve fibers.
Miller-Keane Encyclopedia and Dictionary of Medicine, Nursing, and Allied Health, Seventh Edition. © 2003 by Saunders, an imprint of Elsevier, Inc. All rights reserved.

nerve impulse

n.
A wave of physical and chemical excitation along a nerve fiber in response to a stimulus, accompanied by a transient change in electric potential in the membrane of the fiber.
The American Heritage® Medical Dictionary Copyright © 2007, 2004 by Houghton Mifflin Company. Published by Houghton Mifflin Company. All rights reserved.

nerve impulse

The wave-like progression of electrical depolarization that passes along a stimulated nerve fibre. The nerve impulse results from a movement of positive and negative ions across the membrane of the fibre.
Collins Dictionary of Medicine © Robert M. Youngson 2004, 2005

nerve impulse

the message conducted along the AXON of a NERVE (1). The impulse is a propagated negative charge on the outside of the membrane which results from a wave of DEPOLORIZATION passing along an axon. The RESTING POTENTIAL is reversed and becomes an ACTION POTENTIAL, and this passes down the axon at between 1 and 100 ms, depending on the diameter of the fibre, the presence of a MYELIN SHEATH, temperature, species of animal etc. Once an impulse is initiated it progresses without degeneration, and the strength or nature of the stimulus does not affect it; it either is generated or it is not (ALLORNONE LAW). Varying stimuli produce varying numbers of impulses (see SUMMATION). After each impulse there is a REFRACTORY PERIOD during which a second impulse may not pass.
Collins Dictionary of Biology, 3rd ed. © W. G. Hale, V. A. Saunders, J. P. Margham 2005
References in periodicals archive ?
There are billions of nerve impulses in the body and these are always producing complex human electromagnetic fields.
Glial cells, like neurons, have membrane receptors and channels, but they do not conduct nerve impulses in the same way.
Another issue dealt with in considerable detail was the mechanisms of the conduction of nerve impulses and the ways this conduction can fail, particularly in demyelinating diseases, such as multiple sclerosis (MS).
The new data support earlier studies that charted cortical reorganization in monkeys after researchers cut nerve impulses to the animals' limbs.
These cells trigger nerve impulses that pass via the optic nerve to the brain, where visual images are then formed.
The spine uses nerve impulses to communicate with different parts of the body.
Betacarotene is converted by the body into the form of Vitamin A called retinol that's used by cells in the eyes that detect light and convert it into nerve impulses.
9,358,152, combines high frequency, low amplitude vibration and a thermal treatment pack that can add cooling to disrupt nerve impulses of pain.
MS is a debilitating disease of the central nervous system in which nerve impulses within the brain, and between the brain and other parts of the body, are disrupted.
The study is thought to be the first to demonstrate a telepathic link based on nerve impulses, allowing one person to guess what is on another's mind.
Light striking the retina initiates a cascade of chemical and electrical events that ultimately trigger nerve impulses. These are sent to various visual centers of the brain through the fibers of the optic nerve.