Least thoracic splanchnic nerve

Least thoracic splanchnic nerve is a visceral sympathetic nerve which arises from the 12th thoracic ganglion of the sympathetic chain, on either side. The nerve courses ventrally and medially as it pierces the crus of the diaphragm–along with the lesser splanchnic nerve–to terminate at the renal ganglion within the renal plexus.

Like most other splanchnic nerves, the least thoracic splanchnic nerve contains pre-ganglionic sympathetic neurons, which arise from the lateral gray horns of spinal cord and traverse un-relayed through the sympathetic trunk. They synapse with cell bodies of post-ganglionic sympathetic neurons within the renal ganglion. From here onwards, the post-ganglionic sympathetic neurons invest the renal arteries and their branches to reach the kidneys for innervation.