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.
(zoology)
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 ?
If an earthworm suffers amputation, and a portion of the nerve cord near the cut is removed, regeneration fails.
A notochord is a skeletal component, not a primitive nerve cord.
Each focal spot impinges on a bundle of nerves that feeds into a larger nerve cord, the researchers observed by microscopy.
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.
The severed nerve cord was enough to bring us down," Whittaker said.