How many spinal nerves emerged from the spinal cord and how are they named?

Explanation

Spinal nerves: 31 pairs of spinal nerves emerge out from the spinal cord through spaces called the intervertebral foramina found between the adjacent vertebrae. The spinal nerves are named according to the region of vertebral column from which they originate.
(i) Cervical nerves (8 pairs)
(ii) Thoracic nerves (12 pairs)
(iii) Lumbar nerves (5 pairs)
(iv) Sacral nerves (5 pairs)
(v) Coccygeal nerves ( pair)
Each spinal nerve is a mixed nerve containing both afferent (sensory) and efferent (motor) fibres. It originates as two roots:1) a posterior dorsal root with a ganglion outside the spinal cord and 2) an anterior ventral root with no external ganglion.