Question

Discuss the regulation of digestive function by the intrinsic (myenteric vs. submucosal plexus) and extrinsic nervous systems. (in paragraph form)

Answer 1

The Intrinsic nervous system has two plexuses: 1). Myenteric and 2). Submucosal. The Myenteric plexus plays role in increasing the tone of the gut and the speed and intensity of contractions whereas the submucosal plexus plays role in local secretion, absorption and muscle movements.

Stomach and esophagus are dependent on extrinsic nervous system consisting of parasympathetic and sympathetic pathways. The sympathetic nervous system has inhibitory effect on Gastrointestinal muscles and gives tonic inhibitory influence on mucosal secretion and also regulates GI blood flow by vasoconstriction. Whereas the parasympathetic nervous system has both excitatory and inhibitory control on gastric and intestinal tone and motility of GI tract.