Peptide YY (PYY) is released from which part of the digestive system?

Peptide YY (PYY) is a hormone that plays a crucial role in regulating appetite and digestion. It is primarily secreted by the L cells located in the distal gut, specifically the ileum and colon. When food enters the digestive system, especially high-protein or fatty meals, these L cells release PYY into the bloodstream. The release of PYY helps to reduce appetite by signaling the brain to increase feelings of fullness and slow down gastric motility, allowing for better nutrient absorption and facilitating digestive processes.

The secretion of PYY is particularly significant after meals. The distal gut's response, which involves the release of PYY, is part of a complex hormonal signaling system that regulates energy homeostasis and satiety. Other parts of the digestive system, like the stomach and small intestine, release different hormones and do not primarily synthesize PYY. The liver, while essential in metabolism and nutrient processing, is not involved in the production of PYY. Hence, the correct identification of the distal gut as the source of PYY reflects an understanding of its physiological role in the digestive system.