Enterogastric reflex explained

The enterogastric reflex is one of the three extrinsic reflexes of the gastrointestinal tract, the other two being the gastroileal reflex and the gastrocolic reflex. The enterogastric reflex is stimulated by duodenal distension. It can also be stimulated by a pH of 3-4 in the duodenum and by a pH of 1.5 in the stomach. Upon initiation of the reflex, the release of gastrin by G-cells in the antrum of the stomach is shut off. This in turn inhibits gastric motility and the secretion of gastric acid (HCl).^[1] __TOC__

Emptying inhibitory factors

The stomach's contents are inhibited from emptying into the small intestine by:

• duodenal distension^{[2] [3]}
• duodenal acidic pH^[4]
• duodenal hypertonicity^{[5] [6]}
• increased osmolarity of gastric chyme
• sympathetic stimulation
• intense pain
• Cholecystokinin, Secretin, Vasoactive intestinal peptide
• Nitric oxide, somatostatin from D cells

Emptying stimulatory factors

The stomach's contents empty through the pylorus, allowing digestion to proceed, when there is:

• parasympathetic stimulation
• increased volume and fluidity of gastric contents^[7]

Notes and References

1. Web site: Gastrointestinal Reflex Pathways. 22 July 2018. LibreTexts. 27 October 2019.
2. April 1992. Vagal and splanchnic sensory pathways mediate inhibition of gastric motility induced by duodenal distension. American Journal of Physiology. Gastrointestinal and Liver Physiology. 262. G603–G608. 10.1152/ajpgi.1992.262.4.G603. 1566842. Holzer. H. H.. Raybould. H. E.. 4.
3. Web site: Enterogastric Reflex . Encyclopedia.com . 27 October 2019.
4. The slowing of gastric emptying by nine acids. The Journal of Physiology. 201. 161–179. 1351638. 1969. Hunt. J. N.. Knox. M. T.. 1. 5773550. 10.1113/jphysiol.1969.sp008749.
5. Web site: Factors That Regulate Gastric Emptying . Physiology Plus . 22 November 2019. https://web.archive.org/web/20190427102846/http://physiologyplus.com/factors-that-regulate-gastric-emptying/ . 2019-04-27 .
6. Control of gastric emptying by osmolality of duodenal contents in man . Gastroenterology . May 1975 . 68 . 1126594 . 23 November 2019. Meeroff . J. C. . Go . V. L. . Phillips . S. F. . 5 Pt 1 . 1144–51 . 10.1016/S0016-5085(75)80228-9 . free .
7. Web site: Nervous System of the Digestive System - Gastrointestinal Reflex Pathways. Boundless. 31 March 2016.