Ventral nerve cord

[2] The ventral nerve cord coordinates neural signaling from the brain to the body and vice versa, integrating sensory input and locomotor output.

[1] Because arthropods have an open circulatory system, decapitated insects can still walk, groom, and mate — illustrating that the circuitry of the ventral nerve cord is sufficient to perform complex motor programs without brain input.

Pairs of hemisegments, corresponding to the left and right side of the ventral nerve cord, are connected horizontally by fibrous tracts called commissures.

[5] The presumed common ancestral structure is rarely observed; instead the ventral nerve cords of most insects show extensive modification as well as convergence.

[4] The insect ventral nerve cord develops according to a body plan based on a segmental set of 30 paired and one unpaired neuroblasts.

The anatomy of an insect , with the brain (#5) in teal green and ventral nerve cord (#19) in darkblue .
Left, a schematic of the Drosophila central nervous system, including the brain and ventral nerve cord . Right, a cross section of the ventral nerve cord, illustrating sensory input and motor output. Adapted with permission from. [ 1 ]