Lower half of right sympathetic cord. (Sacral splanchnic nerves not pictured, but upper sacral ganglion and hypogastric plexus are labeled at bottom left.)
The sacral sympathetic nerves contain a mix of preganglionic and postganglionic sympathetic fibers, but mostly preganglionic. They also contain general visceral afferent fibers. They are found in the same region as the pelvic splanchnic nerves, which arise from the sacral spinal nerves to provide parasympathetic fibers to the inferior hypogastric plexus.