24 Internal Anatomy – Nervous System

Internal Anatomy – Nervous System

The nerve cord in insects is ventral (ours is dorsal).

There is a ganglion, a concentration of nervous tissue, associated with each segment. Each segment is, therefore, somewhat autonomous, but all segments are coordinated by the brain.

These photos show nerves extending from each ganglion, communicating with various parts of the body. The right-hand photo is of a ganglion in the thorax (legs, wings, etc.).

The nerve cord extends forward to just below the esophagus. Two branches wrap around the esophagus and other internal structures, then rejoin to form the brain. With the back of the head removed, the main structures visible are optic lobes, associated with the compound eyes.