which part of the earthworm serves as its brain
Best Answer: The earthworm has a cerebral ganglion, which serves as its brain. It is connected to the rest of the body by means of a ventral nerve cord.There is a swelling, called a ganglion, in each segment.. These two cerebral ganglia are connected to the rest of the body as follows: Sensory nerves leave the brain and run forward into the prostomium (extreme anterior end) and first segment. From there, a ventral nerve cord connects all the segments of the worm. 3.