What is Nerve Cord ?
1 Answer
The dorsal nerve cord is a bundle of nerve fibers in the embryo that will eventually develop into the spinal cord and the brain.
Explanation:
Assuming we're not referring to invertebrates, in which case the answer would be different, the dorsal nerve cord is found in the embryo. It is a hollow tube that runs dorsally across the body (see image below) and contains a bundle of nerve fibers.
It is formed from the ectoderm and will eventually develop into the spinal cord and the brain, also known as the nervous system.
In invertebrates, instead of a dorsal nerve cord, there is a ventral nerve cord (see image below). The ventral nerve cord is typically a pair of nerve cords with trunks that are partially fused.
When we say "ventral nerve cord," we are referring to this fused pair. Technically, the ventral nerve cord is two nerve cords that are fused together to some degree (the degree varies depending on the species). For a really detailed explanation of this idea, check out this link and scroll down to "the ventral nerve cord." The image below gives a hopefully helpful visual of this concept in a grasshopper.
To learn more, check out this link.