The Earthworm
The Earthworm's nervous system is composed of three parts: the central nervous system (CNS), peripheral nervous system and the sympathetic nervous system. The central nervous system is mainly made up of a primary ganglia, a sub ganglia, and circum-pharyngeal, and a ventral nerve cord. All of these have a certain arrangement that form a nerve ring around the pharynx. The ventral nerve cord has a ganglion with three giants axons. The peripheral nervous system is made of eight to ten nerves that come from the cerebral ganglia to give to the prostomium, buccal chamber, and the pharynx. The sympathetic nervous system is made up of nerve plexuses in the epidermis and alimentary canal. These nerves branch off for muscle plexus.
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