[Durgical](https://durgical.com/en/) › [DurgiPedia](https://durgical.com/en/durgipedia/) › [Physiology](https://durgical.com/en/physiology/) › [Gastrointestinal](https://durgical.com/en/physiology/#s-gi) › Gastrointestinal hormones [Physiology](https://durgical.com/en/physiology/) · [Gastrointestinal](https://durgical.com/en/physiology/#s-gi) # Gastrointestinal hormones - Table to know - Exam priority: high The gut makes its own hormones: they report what food arrived and tune acid, enzymes, bile, emptying and appetite. Updated 2026-11-01 Also called: Gut peptides, Digestive hormones **See it in 3D:** [Stomach](https://durgical.com/en/anatomy/stomach/) · [Duodenum](https://durgical.com/en/anatomy/duodenum/) · [Jejunum](https://durgical.com/en/anatomy/jejunum/) · [Ileum](https://durgical.com/en/anatomy/ileum/) · [Pancreas](https://durgical.com/en/anatomy/pancreas/) · [Gallbladder](https://durgical.com/en/anatomy/gallbladder/) ## Key points - Gastrin (G cells of the antrum): stimulated by peptides, distension and the vagus (via GRP); inhibited by acid (pH - There are three signalling routes: endocrine (gastrin, CCK, secretin, GIP, motilin), paracrine (somatostatin, histamine) and neurocrine (VIP, GRP, nitric oxide, substance P). - Gastrin and CCK share the same C-terminal end, so CCK is a weak agonist at the gastrin receptor. - VIP is a relaxing, secretory neurotransmitter; a tumour that makes it (VIPoma) causes watery diarrhea, hypokalemia and achlorhydria. ## Gut hormones: source, trigger and actions | Hormone | Cell and site | Main trigger | Key actions | | --- | --- | --- | --- | | [Gastrin](https://durgical.com/en/conditions/peptic-ulcer-disease/) | G cells, gastric antrum and duodenum | Peptides and amino acids, distension, vagus (GRP); inhibited by pH - Gastrinoma: acid hypersecretion, refractory jejunal ulcers and diarrhea because lipase is inactivated in an over-acid duodenum. - Autoimmune atrophic gastritis or long-term proton pump inhibitor use: little acid → gastrin rises because the brake is gone (secondary hypergastrinemia). - Incretins are the physiological basis for GLP-1 analogues in type 2 diabetes and obesity. ## Memory aid 'Protein asks for acid, fat asks for bile, acid asks for bicarbonate': gastrin, CCK and secretin each answer what has arrived. ## Test yourself Think of the answer, then tap the question to see it. ## Why does oral glucose cause more insulin secretion than the same amount given intravenously? Passing through the gut releases GIP (K cells) and GLP-1 (L cells), the incretins, which amplify glucose-dependent insulin secretion. ## A patient with multiple ulcers has very high gastrin and a gastric pH of 1. What diagnosis fits and why is gastrin not suppressed? Gastrinoma (Zollinger–Ellison). Tumour gastrin escapes the somatostatin brake that acid normally triggers, so it stays high despite the low pH. ## Which hormone rises when a fatty meal reaches the duodenum, and what does it do to the gallbladder and stomach? CCK. It contracts the gallbladder, relaxes the sphincter of Oddi, stimulates pancreatic enzymes and slows gastric emptying to give digestion time. ## What stimulus releases secretin, and what secretion does it produce from the pancreas? Acid entering the duodenum (pH below about 4.5). Secretin makes pancreatic duct cells secrete a bicarbonate-rich fluid that neutralizes chyme. [Add to my cards (4)](https://durgical.app/estudiar/?add=/en/physiology/gastrointestinal-hormones/) ## See it in 3D The structures of Durgical's 3D anatomy where it happens. - [Stomach](https://durgical.com/en/anatomy/stomach/) - [Duodenum](https://durgical.com/en/anatomy/duodenum/) - [Jejunum](https://durgical.com/en/anatomy/jejunum/) - [Ileum](https://durgical.com/en/anatomy/ileum/) - [Pancreas](https://durgical.com/en/anatomy/pancreas/) - [Gallbladder](https://durgical.com/en/anatomy/gallbladder/) ## Related topics - [Gastric acid secretion](https://durgical.com/en/physiology/gastric-acid-secretion/) - [Exocrine pancreatic secretion](https://durgical.com/en/physiology/exocrine-pancreatic-secretion/) - [Bile and the enterohepatic circulation](https://durgical.com/en/physiology/bile-and-the-enterohepatic-circulation/) - [Gastric motility and emptying](https://durgical.com/en/physiology/gastric-motility-and-emptying/) - [Appetite hormones: leptin, ghrelin and incretins](https://durgical.com/en/physiology/appetite-hormones-leptin-ghrelin-and-incretins/) - [Islets and insulin: secretion and actions](https://durgical.com/en/physiology/islets-and-insulin-secretion-and-actions/) - [The enteric nervous system, slow waves and GI control](https://durgical.com/en/physiology/the-enteric-nervous-system-slow-waves-and-gi-control/) ## Related conditions - [Peptic ulcer disease](https://durgical.com/en/conditions/peptic-ulcer-disease/) - [Type 2 diabetes mellitus](https://durgical.com/en/conditions/type-2-diabetes-mellitus/) - [Obesity](https://durgical.com/en/conditions/obesity/) - [Gallstones (cholelithiasis)](https://durgical.com/en/conditions/gallstones/) ## In Biochemistry - [G protein-coupled receptors and cAMP](https://durgical.com/en/biochemistry/topics/g-protein-coupled-receptors-and-camp/) - [Insulin signalling](https://durgical.com/en/biochemistry/topics/insulin-signalling/) [← All of physiology](https://durgical.com/en/physiology/) Educational physiology content; not a diagnostic or treatment guide and no substitute for a health professional's advice. Values are approximate references. No doses are given. Sources: [23.2 Digestive System Processes and Regulation](https://openstax.org/books/anatomy-and-physiology-2e/pages/23-2-digestive-system-processes-and-regulation) (OpenStax (Rice University), 2022); [23.4 The Stomach](https://openstax.org/books/anatomy-and-physiology-2e/pages/23-4-the-stomach) (OpenStax (Rice University), 2022); [23.6 Accessory Organs in Digestion: The Liver, Pancreas, and Gallbladder](https://openstax.org/books/anatomy-and-physiology-2e/pages/23-6-accessory-organs-in-digestion-the-liver-pancreas-and-gallbladder) (OpenStax (Rice University), 2022); Hall JE. Guyton and Hall Textbook of Medical Physiology, 13th ed. (ch. 65). Reference book used to check facts; its text and figures are not reproduced (Elsevier, 2016). ## **Spotted a mistake?** We are always improving for the community. Tell us what is wrong and our team will review it. Report a mistake Representative model, for educational purposes only. --- Source: https://durgical.com/en/physiology/gastrointestinal-hormones/ License: CC BY 4.0 (https://creativecommons.org/licenses/by/4.0/). Cite as: DurgiPedia (durgical.com), https://durgical.com/en/physiology/gastrointestinal-hormones/