axon

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axon:

see nervous systemnervous system,
network of specialized tissue that controls actions and reactions of the body and its adjustment to the environment. Virtually all members of the animal kingdom have at least a rudimentary nervous system.
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; synapsesynapse
, junction between various signal-transmitter cells, either between two neurons or between a neuron and a muscle or gland. A nerve impulse reaches the synapse through the axon, or transmitting end, of a nerve cell, or neuron.
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The Columbia Electronic Encyclopedia™ Copyright © 2013, Columbia University Press. Licensed from Columbia University Press. All rights reserved. www.cc.columbia.edu/cu/cup/
The following article is from The Great Soviet Encyclopedia (1979). It might be outdated or ideologically biased.

Axon

 

a neurite, or axis cylinder; the process of a nerve cell along which neural impulses proceed from the cell body to innervated organs and other nerve cells.

Only one axon branches off each neuron, or nerve cell. The nutrition and growth of the axon depends on the neuron body; upon transection of the axon, its peripheral portion dies, but the central portion preserves its viability. Large animals possess axons—for example, those proceeding from the spinal cord to the extremities—that may reach a length of one meter or more when their diameter is several millimicrons (mμ). In some animals—for example, squid and fish—huge axons are found which measure hundreds of mμ in thickness. In axoplasm—that is, the protoplasm of axons—there are extremely thin fibrils, known as neurofibrils, as well as mitochondria and the endoplasmic network. Depending on whether axons are covered with a myelic (fatty) membrane or not, they are known as medullated or nonmedullated nerve fibers. The structure of the membranes and the diameters of the axons that constitute the nerve fiber are the factors that determine the rate of stimulus transmission along the nerve. The terminal sections of the axon, or terminals, branch off and make contact with other nerve, muscle, and gland cells. Stimuli are transmitted through these contact points, which are known as synapses. A nerve is a collection of axons.

The Great Soviet Encyclopedia, 3rd Edition (1970-1979). © 2010 The Gale Group, Inc. All rights reserved.

axon

[′ak‚sän]
(neuroscience)
The process or nerve fiber of a neuron that carries the unidirectional nerve impulse away from the cell body. Also known as neuraxon; neurite.
McGraw-Hill Dictionary of Scientific & Technical Terms, 6E, Copyright © 2003 by The McGraw-Hill Companies, Inc.
References in periodicals archive ?
Upon electro diagnostic studies and examination, the GBS variants distribution was as follows: Acute inflammatory demyelinating polyradiculo-neuropathy variant (AIDP) in 49 (39.2%) of the patients, acute motor axonal neuropathy (AMAN) variant in 67 (53.6%), 6(4.8%) patients having mixed (axonal + demyelinating) variety as shown in table-IIII.
Parameters like severity on admission, axonal involvement, severity at nadir, latency to nadir, having an age over 40 or 50 years, longer duration of the plateau phase, and antecedent gastroenteritis are considered to be associated with a worse recovery (18).
Calpain activation by wingless-type murine mammary tumor virus integration site family, member 5A (Wnt5a) promotes axonal growth.
Giant axonal neuropathy: A clinicoradiopathologic diagnosis.
In this review, we will discuss some of the major contributing factors to the prevention of plasticity, sprouting, and axonal regeneration after SCI.
Axonal loss was estimated by Bielschowsky silver staining using the following 4-point scale: 0, no axonal loss; 1, a few foci of superficial axonal loss involving less than 25% of the tissues; 2, foci of deep axonal loss that encompassed over 25% of the tissue; and 3, diffused and widespread axonal loss [12, 20].
The diagnosis of GARS-associated axonal neuropathy is made based on phenotypical presentation, electromyography (EMG), and genetic testing.
An EMG/NCS was also done, showing pure motor neuropathy and myopathic changes at proximal muscle and a normal sensory picture, suggestive of acute motor axonal neuropathy for early Guillain-Barre syndrome.
Besides brain injury and SCI, axonal damage is a factor in many other disorders and diseases, including multiple sclerosis and neurodegenerative conditions.
Stroke induces a process of axonal sprouting in peri-infarct tissue and it is correlated in location and magnitude with functional recovery after stroke (19-22).