Enteric parasympathetic nerves

The enteric parasympathetic nerves constitute the extrinsic parasympathetic innervation of the gastrointestinal tract, primarily originating from the vagus nerve and the pelvic splanchnic nerves [1][2]. These nerves project to the enteric nervous system (ENS), where they synapse with postganglionic neurons in the myenteric and submucosal plexuses to modulate essential digestive functions [2][3]. Their primary biological role is to stimulate gastrointestinal motility, enhance glandular secretions such as gastric acid and digestive enzymes, and induce vasodilation to support the "rest and digest" physiological state [1][3]. Dysfunction in this neural pathway is implicated in various motility disorders, including gastroparesis, achalasia, and chronic constipation, as well as inflammatory conditions via the cholinergic anti-inflammatory pathway [3][4]. While not a single molecular target, these nerves are pharmacologically modulated through drugs that act on cholinergic signaling, such as muscarinic agonists like bethanechol or acetylcholinesterase inhibitors like neostigmine [1]. Conversely, muscarinic antagonists are used to inhibit overactive parasympathetic signaling in conditions characterized by hypermotility or excessive secretion [1]. Sources: [1] Tindle J, Tadi P. Neuroanatomy, Parasympathetic Nervous System. StatPearls. 2023. [2] Furness JB. The enteric nervous system and gastrointestinal innervation: integrated and independent control. Adv Exp Med Biol. 2014. [3] Browning KN, Travagli RA. Central nervous system control of gastrointestinal motility and secretion and modulation of gastrointestinal functions. Comprehensive Physiology. 2014. [4] Bonaz B, Bazin T, Pellissier S. The Vagus Nerve at the Interface of the Microbiota-Gut-Brain Axis. Front Neurosci. 2018.

Other names

Parasympathetic division of the enteric nervous systemExtrinsic parasympathetic gut innervationVagal and sacral parasympathetic supply to the gastrointestinal tract

Pharmacological agents interact with this system by modulating cholinergic neurotransmission, primarily through the activation or inhibition of muscarinic and nicotinic receptors located on enteric neurons and effector cells like smooth muscle and glands [1][3].