Thoracic splanchnic nerves

Thoracic splanchnic nerves arise from the sympathetic trunk in the thorax and travel inferiorly to provide sympathetic innervation to the abdomen. The nerves contain preganglionic sympathetic and visceral afferent fibers.

There are three main thoracic splanchnic nerves:

The nerve's origins can be remembered by the "4-3-2 rule", accounting for the number of ganglia giving rise to each nerve. However, different sources define the nerves in different ways, so this rule may not always be reliable.