Sympathetic input to the gut comes from the sympathetic chain next to the thoracic vertebrae. The upper nerve supply leaves the sympathetic chain by the greater splanchnic nerve

Thoracic splanchnic nerves

Thoracic splanchnic nerves are splanchnic nerves that arise from the sympathetic trunk in the thorax and travel inferiorly to provide sympathetic innervation to the abdomen...

 and synapses in the celiac ganglion

Celiac ganglia

The celiac ganglia or coeliac ganglia are two large irregularly shaped masses of nerve tissue in the upper abdomen. Part of the sympathetic subdivision of the autonomic nervous system , the two celiac ganglia are the largest ganglia in the ANS, and they innervate most of the digestive tract.They...

 before proceeding onto the foregut. Below this the lesser splanchnic nerve

Thoracic splanchnic nerves

Thoracic splanchnic nerves are splanchnic nerves that arise from the sympathetic trunk in the thorax and travel inferiorly to provide sympathetic innervation to the abdomen...

 leaves the sympathetic chain and synapses at the aorticorenal ganglion

Aorticorenal ganglion

Sympathetic input to the gut comes from the sympathetic chain next to the thoracic vertebrae. The upper nerve supply leaves the sympathetic chain by the greater splanchnic nerve and synapses in the celiac ganglion before proceeding onto the foregut...

 before going onto also supply the kidney and upper ureter. Below this the least splanchic nerve

Thoracic splanchnic nerves

Thoracic splanchnic nerves are splanchnic nerves that arise from the sympathetic trunk in the thorax and travel inferiorly to provide sympathetic innervation to the abdomen...

leaves the sympatheic chain to synapse at the "renal plexus".

External links

The preganglionic ventral root of the least splanchnic nerve originates from vertebral level T12, and enter the abdominal cavity by piercing the crus of the diaphragm.