Final answer:
The pre-ganglionic cell bodies of the sympathetic nervous system originate in the spinal cord (Thoracic and Lumbar regions).
Step-by-step explanation:
The pre-ganglionic cell bodies of the sympathetic nervous system originate in the spinal cord (Thoracic and Lumbar regions). These cell bodies are located in the lateral horn of the thoracolumbar spinal cord. From there, the axons project to ganglia adjacent to the vertebral column through the ventral spinal roots, forming the sympathetic chain ganglia.