•As described before, 31 pairs of spinal nerves emerge from the spinal cord:
•8 cervical, 12 thoracic, 5 lumbar, 3 sacral and 1 coccygeal
•Each spinal segment gives off a nerve root from the front- the ventral root and a root from the back- the dorsal root on both sides. The ventral and dorsal root from each side come together and join each other to form one spinal nerve.
•This way, each spinal segment gives off one pair of spinal nerves, one on each side. Each spinal nerve carries motor fibres from the ventral root sensory fibres to the dorsal root.
•Other than this, spinal nerves from cervical, thoracic and lumbar segments also carry sympathetic nerve fibres that control the autonomic (involuntary) actions.
•Each spinal nerve supplies specific region of the body and specific organs and muscles. The details of this functional distribution is in module 4.