Question

Write a detail note on nervous system in leech.

Answer 1

Nervous system in leech:

1. The central nervous system of leech consists of a nerve ring and a paired ventral nerve cord.
2. The nerve ring surrounds the pharynx and is formed of suprapharyngeal ganglion (brain), circumpharyngeal connective and subpharyngeal ganglion.
3. The subpharyngeal ganglion lies below the pharynx and is formed by the fusion of four pairs of ganglia.