The nervous system of scorpions consists of a central nervous system with a brain, sub-oesophageal ganglia connected by circumoesophageal connectives, and a double ventral nerve cord with several ganglia. The brain controls complex behaviors and locomotion while the sub-oesophageal ganglia innervate the chelicerae and first segments. Nerves emanate from the ganglia of the central nervous system to innervate structures like eyes, mouthparts, limbs, book lungs and other organs. The peripheral nervous system includes lateral nerves from the sub-oesophageal ganglia and paired nerves from each ganglion of the ventral nerve cord.

1. NERVOUS SYSTEM
The nervous system consists of a central nervous system, a peripheral
nervous system and a visceral nervous system
The central nervous system includes a brain or supraoesophageal ganglia, sub-
oesophageal ganglia which is connected to brain by short circumoesophageal
connectives,three free mesosomal ganglia,four free metasomal ganglia a double ventral
ganglionated nerve cord which is similar to the spinal cord in vertebrates.
1.Brain
The brain is composed of two large ganglia situated above the esophagus. The upper lobe
(protocerebrum) of the top ganglion processes optic information and is the origin of
complex behaviours, while the lower lobe (tritocerebrum) mainly controls the normal
body functions. The bottom ganglion innervates the chelicerae. Locomotion is controlled
by both ganglia. The nerve cord of the animal consists of seven ganglia connected by
pairs of fibres.

2. • 2. Sub-oesophageal ganglia:
• It is formed by the fusion of ten pairs of ganglia belonging to embryonic 2
to 11 segments and located ventromedially below the oesophagus.
• 3. Circumoesophageal connectives:
• A pair of short and stout nerves arise from the brain, one on each side,
encircle the oesophagus and unite ventrally with the sub-oesophageal
ganglia.
• 4. Ventral nerve cord:
• A double ventral nerve cord formed by the union of two solid nerve cords
runs posteriorly from the sub-oesophageal ganglia up to the fourth seg-
ment of the metasoma. The nerve cord bears three pre-abdominal ganglia
in the mesosoma and four post-abdominal ganglia in the metasoma, the
last one formed by the fusion of two ganglia of the 18 and 19 segments and
located in the fourth metasomal segment.

3. • Peripheral nervous system:
• Nerves arising from the ganglia of the central nervous system:
• 1. The brain gives off paired nerves to median and lateral eyes and
rostrum and a number of fine nerves to the walls of the preoral cavity,
pharynx, oesophagus and adjoining structures.
• 2. Six pairs of lateral nerves emanating from the sub-oesophageal ganglia
innervate the chelicerae, pedipalpi and four pairs of walking legs.
• 3. Two to four pairs of vagus nerves arising from the sub-oesophageal
ganglia run posteriorly to supply the heart and alimentary canal, genital
operculum, the pectines and the first two pairs of book-lungs in the
mesosoma.
• 4. Paired nerves emanate from each ganglion of the ventral nerve cord
and innervate the structures in the corresponding segments. Nerves from
the first two pre-abdominal ganglia supply the last two pairs of book-
lungs