Nerve Cord

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Related to Nerve Cord: notochord

nerve cord

[′nərv ‚kȯrd]
(invertebrate zoology)
Paired, ventral cords of nervous tissue in certain invertebrates, such as insects or the earthworm.
Dorsal, hollow tubular cord of nervous tissue in chordates.
McGraw-Hill Dictionary of Scientific & Technical Terms, 6E, Copyright © 2003 by The McGraw-Hill Companies, Inc.
The following article is from The Great Soviet Encyclopedia (1979). It might be outdated or ideologically biased.

Nerve Cord


a structure within the central nervous system of annelids and arthropods. The nerve cord is situated on the ventral side of the body, under the gut. It is connected to the cerebral ganglia. The nerve cord consists of a pair of partially fused longitudinal nerve trunks, called connectives, and of pairs of segmental ganglia that innervate each of the body segments. The primitive form of the nerve cord, which occurs in some primitive annelids, polychaetes, and onychophorans, is scaliform, having widely spaced trunks and long commissures between the ganglia.

The Great Soviet Encyclopedia, 3rd Edition (1970-1979). © 2010 The Gale Group, Inc. All rights reserved.
References in periodicals archive ?
The mean recoveries of rotenone in the hemolymph, midgut, ventral nerve cord, brain, and excreta were within the ranges of 80.15 to 110.46%, 87.66 to 113.09%, 86.97 to 111.67%, 84.30 to 92.35%, and 77.76 to 104.31%, respectively; the relative standard deviations of hemolymph, midgut, ventral nerve cord, brain, and excreta were within 3.43 to 7.21%, 3.00 to 12.79%, 4.01 to 11.40%, 5.35 to 9.55%, and 2.02 to 12.56%, respectively.
The electron-dense penetrative fibers, or tonofilaments, are also found as cytoplasmic components of the sheath cells, but not in the axonal bundles surrounding giant axons of the ventral nerve cord of a maldanid polychaete, Asychis elongata (Hartline and Kong, 2009).
Before the 64-cell stage, the presumptive notochord/ nerve cord cells divide into presumptive notochord cells and presumptive nerve cord cells (purple cells and blue cells in Fig.
Interesting features of the leech nerve cord structure can explain the story of the leech neurobiology.
Hereby, molluscan-entoproct tetraneury is not merely restricted to the existence of four longitudinal nerve cords, but rather is defined by a nervous system that exhibits one pair of ventral (pedal) nerve cords with associated serotonergic perikarya and commissures, as well as one pair of lateral (visceral) nerve cords that do not run in the same plane as the pedal cords but more dorsal to them (Fig.
In early juveniles, IR was first observed in the NS of the tube feet and more faintly in the circumoral nerve ring and radial nerve cords of the CNS (Fig.
Each focal spot impinges on a bundle of nerves that feeds into a larger nerve cord, the researchers observed by microscopy.
Nerve system visualized through CLSM of anti-serotonin immunoreactivity shows ventral nerve cord, apparently intra-epidermal, separated into two parts along at least part of trunk, lying between oviduct and circular muscle layer (Fig.
For example, the arthropod's nerve cord, its version of a spinal cord, rests in the ventral side.
That protein causes the axons to grow dorsally, toward the top of the nematode, instead of taking their usual route along the side of the animal or down toward the ventral nerve cord, the Canadian team reports in the July 22 NATURE.
Unique to the octopus arm, stereotypical bend propagation can be evoked in an isolated arm by electrically stimulating the axonal tract of the arm nerve cord or by applying tactile stimulation to the skin or suckers.