Ganglion (pl. ganglia)
Reference work entry
A mass of nervous tissue, and the basic functional unit of the central nervous system. Many insects have three thoracic ganglia (the pro-, meso-, and metathoracic ganglia) in the thoracic region, though in others the meso- and metathoracic ganglia are fused. Each thoracic ganglion (Fig. 12) sends motor axons to the leg muscles of its respective segment, and receives input from sensor receptors in the legs. The meso- and metathoracic ganglia innervate the wing muscles. Ganglia also are found in the abdominal segments, though fusion of ganglia occurs here also. Nearly all ganglia support nerves carrying both sensory and motor neurons laterally in the insect’s body.
© Springer Science+Business Media B.V. 2008