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Gastrointestinal Hormones
TOP 10 TAKEAWAY MESSAGES:
Gastrointestinal (GI) Hormones
1. Gastrointestinal hormones regulate caloric balance, hunger/
satiety food digestion, and nutrient utilization via central nervous
system signaling, effects on GI motility, and GI enzyme release.
2. Common GI hormone action in response to eating includes a
decrease in hunger and facilitation of digestion (delayed gastric
emptying, digestive enzyme release, and post-absorptive
nutrient metabolism).
3. The jejunum, the second longest segment of the small intestine,
absorbs the greatest amount of simple sugars, fatty acids,
proteins, minerals and vitamins.
4. The ileum, the longest segment of the small intestine, absorbs
bile salts, vitamin B12, some vitamins and some minerals.
5. After food intake, most GI hormones decrease hunger/increase
satiety.
6. Among the few GI hormones that increase hunger between
meals are ghrelin ("hunger hormone") and neuropeptide Y (NPY).
Positive caloric balance may not always be hunger-related.
7. Illustrative GI hormones produced by the stomach include
ghrelin and gastrin.
8. Illustrative hormones produced by the pancreas include insulin,
glucagon, pancreatic polypeptide (PP), amylin, and somatostatin.
9. Illustrative GI hormones produced by the small intestine include
cholecystokinin (CCK), secretin, motilin, and glucose-dependent
insulinotropic peptide (GIP — also known as gastric inhibitory
peptide).
10. Illustrative GI hormones produced by the ileum and/or large
intestine include fibroblast growth factor (FGF) 19, glucagon-like
peptide-1, glucagon-like peptide-2, oxyntomodulin, and peptide
YY (PYY).
