MO.41 Pila Nervous System

 

Description:

         The nervous system of Pila globosa consists of paired and unpaired ganglia with their commissures and connectives. Commissures are the nerves which establish connections between similar ganglia, while connectives are the nerves which connect two dissimilar or different ganglia.     

         The nervous system of Pila globosa shows two characteristics, firstly most of the ganglia, except the visceral, are concentrated near the buccal mass, secondly the visceral loop is twisted into a figure of 8 due to torsion. The twisted condition of the nervous system is a primitive feature, because in most gastropods there is a secondary bilateral symmetry shown by the ganglia and connectives.