The visceral component is divided into the parasympathetic, sympathetic divisions, enteric division
Enteric Division
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The efferent nervous system to the gastrointestinal (GI) tract refers to the motor pathways that carry signals from the central nervous system (CNS) or enteric nervous system (ENS) to the GI tract to control motility, secretion, and blood flow. It includes both autonomic (sympathetic and parasympathetic) and enteric components. Here’s a detailed breakdown:
Function: Inhibits GI activity (“fight-or-flight”), reduces motility and secretion, and constricts blood vessels.
Pathways:
Preganglionic neurons in the thoracolumbar spinal cord (T5–L2).
Postganglionic neurons in prevertebral ganglia (celiac, superior mesenteric, inferior mesenteric).
Fibers then travel via splanchnic nerves to the GI tract.
Sometimes considered a “semi-autonomous” efferent system within the GI tract.
Composed of:
Myenteric (Auerbach’s) plexus: Controls motility.
Submucosal (Meissner’s) plexus: Controls secretion and local blood flow.
Receives modulatory input from sympathetic and parasympathetic fibers but can function independently.
Summary Table:
| System | Origin | Target | Effect |
|---|---|---|---|
| Parasympathetic | Vagus, Pelvic Splanchnic | Smooth muscle, glands | Stimulate motility & secretion |
| Sympathetic | Thoracolumbar (T5–L2) | Smooth muscle, glands, vasculature | Inhibit motility & secretion, vasoconstriction |
| Enteric | Myenteric & submucosal plexus | GI wall | Local control of motility, secretion, reflexes |
If you want, I can draw a diagram showing all efferent pathways from CNS to GI tract—it makes this much easier to visualize. Do you want me to do that?