Organ and Organ Systems in Animals — Bio Zoology STD 11 — Question

The nervous system of cockroach consists of a nerve ring and a ganglionated double ventral nerve cord. suh-oesophageal ganglion. circum – oesophageaÌ connectives and double ventral nerve cord (see figure). The nerve ring is present around the ocsophagus in the head capsule and is formed by the supra-oesophagial ganglion called the ‘brain’. The brain is mainly a sensory and an endocrine centre and lies above the oesophagus. Sub – oesophageal ganglion is the motor centre that controls the movements of the mouth parts, legs and wings.

it lies below the oesophagus and formed by the fusion of the paired gangalia of mandibular, maxillary and labial segments of the head. A pair of circum – oesophageal connectives is present around the oesophagus. connecting the supra oesophageal ganglia with the sub-ocsophageal ganglion.
The double ventral nerve cord is solid. ganglionated and arises from the sub-oesophageal ganglion and extends up to the 7th abdominal segment. Three thoracic ganglia are one in each thoracic segment and six abdominal ganglia in the abdomen.