Experimental study on the segmental innervation of the spinal cord to the visceral organs

To clarify the segmental innervation of the spinal cord to the visceral organs, selective section of the individual spinal nerve root of the dog in different spinal segment was performed, and the distribution of distal degeneration of myelinated nerve fibers in the sympathetic trunk and in peripheral nerves was observed. From the results obtained, much wide-spread innervation of each spinal segment to the visceral organs was revealed, and an efferent system in the dorsal root of the spinal nerve was confirmed to be related to the visceral organ. Furthermore, widely extended innervation of the vagus nerve to the visceral organ was clarified.