The 1st thoracic nerve is one of thirty-one pairs of spinal nerves that originate from the spinal cord and the uppermost of the twelve (12) thoracic nerves of the torso. Although spinal nerves do not have individual names, they are grouped according to the level from which they stem, and each nerve is numbered in sequence. Hence, there are twelve pairs of thoracic nerves (T1 - T12).