PYY is produced in which areas of the gastrointestinal tract?

PYY, or peptide YY, is a gut hormone primarily produced in response to food intake. It is secreted mainly by the L cells located in the distal small bowel, colon, and rectum. This hormone plays a significant role in regulating appetite and gastrointestinal motility after meals by inhibiting gastric emptying, promoting satiety, and modulating nutrient absorption.

The correct response indicates the specific sites where PYY is predominantly produced, highlighting the role of the distal small bowel and the colon. The presence of PYY in these regions is crucial for the postprandial (after eating) digestive processes and the regulation of food intake through signaling pathways that affect hunger.

In contrast, while the stomach and small intestine are involved in various digestive functions and hormone secretion, they do not primarily produce PYY. The duodenum, being the first section of the small intestine, also does not secrete PYY in significant amounts, as it mainly handles the initial digestion of food and secretion of other hormones like secretin and cholecystokinin. Thus, the understanding of where PYY is produced is essential for grasping its physiological role in energy homeostasis and appetite regulation.