Nervous System

The cockroach's nervous system is built around a nerve ring encircling the oesophagus in the head, formed by the supra-oesophageal ganglion (the "brain," mainly a sensory and endocrine centre) linked by a pair of circum-oesophageal connectives to the sub-oesophageal ganglion below the oesophagus, which is the motor centre controlling the mouthparts, legs and wings. From the sub-oesophageal ganglion, a solid, ganglionated double ventral nerve cord runs backward, with three separate ganglia in the thorax (one per segment) and six in the abdomen, extending to the seventh abdominal segment. A rich set of sense organs serves this system: touch (thigmoreceptors) on the antennae, maxillary palps and cerci; smell (olfactory receptors) on the antennae; taste (gustatory receptors) on the maxillary and labial palps; temperature sensing on the first four tarsal segments of the legs; vibration sensing (chordotonal receptors) on the anal cerci; and sight through a pair o …