: Tracheal system in dorsal view 9HQWUDO FHSKDOLF WUXQN 7KRUDFLF VSLUDFOHV $EGRPLQDO VSLUDFOHV &RPPLVVXUDOWUDFKHD $WULXP 9HQWUDO ORQJLWXGLQDO WUXQN 'RUVDO ORQJLWXGLQDO WUXQN /DWHUDO ORQJLWXGLQDO WUXQN 'RUVDO FHSKDOLF WUXQN , ,, $, $,, $,,, $, $ $ , $ ,,, $ ,, Respiratory system of cockroach is formed of spiracles and tracheal interconnections. Why is it said to be more efficient than that of earthworm? Why inspiration of cockroach is said to be a passive process while it is an active process in man? Cockroaches survive without a head A cockroach can live for about a week without its head.
Due to their open circulatory system, and the fact that they breathe through little holes on each of their body segments, since they are not dependent on the mouth or head to breathe. The cockroach dies later due to starvation XI Std Biology-Zoology Chapter- Nervous System The nervous system of cockroach consists of a nerve ring and a ganglionated double ventral nerve cord , sub- oesophageal ganglion , circum– oesophageal connectives and double ventral nerve cord (Figure . ) . The nerve ring is present around the oesophagus 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- oesophageal ganglion. The double ventral nerve cord is solid, ganglionated and arises from the sub-oesophageal ganglion and extends up to the th abdominal segment.
Three thoracic ganglia are present, one in each thoracic segment and six abdominal ganglia in the abdomen. In cockroach, the sense organs are antennae, compound eyes, labrum, maxillary palps, labial palps and anal cerci. The receptor for touch (thigmo receptors) is located in the antenna, maxillary palps and cerci. The receptor