nerve cord

American  

noun

1. a single hollow tract of nervous tissue that constitutes the central nervous system of chordates and develops into the spinal cord and brain in vertebrates.

2. a solid double strand of nerve fibers along the length of the body in elongate invertebrates, as earthworms and insects, connecting with a pair of nerve ganglia at each body segment.

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Etymology

Origin of nerve cord

First recorded in 1875–80

Example Sentences

The class Mammalia is placed in the phylum Chordata, in which all of the animals have a nerve cord.

From Textbooks • Jan. 1, 2018

The ventral nerve cord is better developed than the dorsal or lateral cords.

From Textbooks • Jan. 1, 2015

A long, thin dorsal hollow nerve cord runs the length of the chordate, along the top.

From Textbooks • Jan. 1, 2015

The nerve cord is ventral in position and bears enlarged nodes or ganglia in each segment.

From Textbooks • Jan. 1, 2015

In this Annelid later the sac in question joins its fellow, passing beneath the nerve cord exactly as in the leech, and also grows out to reach the exterior.

From Encyclopaedia Britannica, 11th Edition, Volume 5, Slice 7 "Cerargyrite" to "Charing Cross" by Various