GLOSSARY

Enteroendocrine Cells
Enteroendocrine cells are specialized epithelial cells that sense luminal and absorbed nutrients and release peptide signals. They communicate with nearby cells, nerves and distant targets.

A network of nutrient signals. Gastrointestinal signaling combines direct nutrient sensing, enteric neural activity, endocrine release and vagal communication. Meal size, composition and gastric emptying affect the response. Several peptides can be released together, so one concentration cannot explain the entire postprandial state.

Specific considerations. Cell identities and hormone combinations are more diverse than a strict one-cell–one-hormone model. Nutrient location, transport and receptor activation help shape the resulting signal.

Appetite and exercise. An acute appetite-hormone change does not necessarily predict later food intake. Exercise duration, intensity, heat and carbohydrate availability can modify both secretion and symptoms. Measurements are most useful when linked with actual intake, tolerance and recovery.