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.

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.

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.
To identify the cellular origin of the tonofilaments, cells near the brain and ventral nerve cord were examined.
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.
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.
IR decreased and merged with that in the developing nerve cord (Fig.
Consistent with the results from other gymnolaemate larvae, two rows of sensory neurons border the ciliated groove and their axonal fibers form a nerve cord that enters the nerve nodule (BCN; Fig.
was undertaken to locate the nerve cord and thus establish the dorsal-ventral axis for Osedax.
We propose that the longitudinal nerve cords of insects and vertebrates derive from one and the same centralized nervous system in their common ancestor," wrote Detlev Arendt and Katharina Nubler-Jung of the Albert Ludwigs University in Freiburg.
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.
Behavioral studies suggest that many of the complex actions performed by octopus arms are organized at the level of the peripheral nerve cord (Altman, 1971; Wells, 1978; Sumbre et al.
The severed nerve cord was enough to bring us down," Whittaker said.