What are the structural features of the nervous system of annelids?

The nervous system of annelids primarily consists of paired nodes, united by the so-called supraopharyngeal ganglion. This node is located in the head section of the body of the worm and a nerve ring extends from it, stretching around the mouth opening. This system plays the role of the brain. Also, a nerve column departs from the ganglion with the same paired nodes, but not strongly developed, located in each segment of the annelid worm’s body. From these nodes, in turn, the entire system of nerves and nerve endings stretches.