How spinal nerves are numbered?

Spinal nerves are numbered according to the region of the spine from which they emerge. There are 31 pairs of spinal nerves: 8 cervical (C1-C8), 12 thoracic (T1-T12), 5 lumbar (L1-L5), 5 sacral (S1-S5), and 1 coccygeal (Co1). Cervical nerves are numbered based on the vertebrae below which they exit, while thoracic, lumbar, sacral, and coccygeal nerves correspond to the vertebrae above which they emerge. This numbering system helps to identify the specific nerve and its associated functions in the body.