Gastrointestinal hormones: gastrin, CCK, secretin, incretins and ghrelin
Where each gut hormone is made, what releases it and what it does, the control of gastric acid secretion through gastrin, histamine and somatostatin, and how the physiology explains hypergastrinaemia, Zollinger-Ellison syndrome, dumping, incretin drugs and post-bariatric hypoglycaemia.
Tier 1Medical sciences concept
Written with AI assistance and fact-checked against the sources below. For exam study, not clinical decisions. How notes are made
At a glance
- Gut hormones come from scattered enteroendocrine cells, not discrete glands. Each cell type sits where its stimulus arrives: acid-sensing S cells in the duodenum, nutrient-sensing L cells in the distal ileum and colon.
- Gastrin drives acid. Secretin neutralises it. CCK delivers enzymes and bile for fat. Somatostatin brakes almost everything.
- GLP-1 and GIP are incretins: they amplify glucose-dependent insulin release. Ghrelin is the one hunger signal; PYY, GLP-1 and CCK signal satiety.
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Sources
- Sleisenger and Fordtran's Gastrointestinal and Liver Disease (11th ed.)Elsevier (Feldman, Friedman, Brandt, 2021), 2021
- Guyton and Hall Textbook of Medical Physiology (14th ed.)Elsevier (Hall and Hall, 2021), 2021
- Nauck MA, Meier JJ. Incretin hormones: their role in health and disease. Diabetes Obes Metab 2018;20 Suppl 1:5-21Diabetes, Obesity and Metabolism, 2018
- Metz DC, Cadiot G, Poitras P, Ito T, Jensen RT. Diagnosis of Zollinger-Ellison syndrome in the era of PPIs, faulty gastrin assays, sensitive imaging and limited access to acid secretory testing. Int J Endocr Oncol 2017;4(4):167-85International Journal of Endocrine Oncology, 2017
- Last updated
- 14 November 2026
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- 14 November 2026 Personal emails, About story and Australian-style copy