X/A-like

cells in the stomach increase ghrelin production to activate the Area Postrema

and enhance gastric emptying.

I-cells

in the upper gut release CCK in response to fatty acids to signal satiety via

vagal afferents, while L-cells release PYY to inhibit NPY/AgRP neurons in the

ARC.

Intramuscular

arrays (IMAs) detect a decrease in gastric wall tension, which triggers the

release of GLP-1 from the colon to stimulate insulin.

L-cells in

the duodenum release CCK to activate POMC neurons in the Arcuate Nucleus (ARC)

directly.