Splanchnic nerve fiber

Splanchnic nerve fibers refer collectively to bundles of visceral autonomic nerve axons that supply the internal organs within the thorax, abdomen, and pelvis. These include both sympathetic preganglionic efferent fibers from thoracic/lumbar/sacral origins and parasympathetic preganglionic efferents from sacral spinal segments S2–S4 ("pelvic splanchnics"). They play essential roles in regulating blood flow, digestion/peristalsis/secretion within the gastrointestinal tract and genitourinary system by transmitting both motor/autonomic commands from the central nervous system as well as sensory information back from viscera—including nociceptive signals involved in visceral pain perception. While important clinically—especially regarding chronic abdominal/pelvic pain management—they do not represent discrete druggable targets at the molecular level but rather complex neural pathways composed primarily of axonal projections bundled together anatomically.

Other names

Splanchnic nervesVisceral autonomic nervesThoracic splanchnic nerves (greater, lesser, least)Lumbar splanchnic nervesSacral splanchnic nervesPelvic splanchnic nerves (nervi erigentes)

Not applicable at the molecular level. For interventions: Nerve block: interruption/blockade prevents transmission of autonomically mediated signals including pain.