Where are K cells and L cells located within the intestine?

K cells and L cells are specialized endocrine cells primarily found in the intestinal mucosa, specifically located in the crypts of Lieberkühn, which are tubular structures lined with epithelial cells in the small intestine. K cells are responsible for secreting gastric inhibitory peptide (GIP), which plays an essential role in glucose metabolism and inhibiting gastric motility. L cells secrete glucagon-like peptide-1 (GLP-1) and peptide YY (PYY), which are involved in regulating insulin secretion and appetite. This localization is critical because being in the crypts allows these cells to effectively sense the contents of the intestinal lumen and release hormones that influence digestion and metabolic processes.

Understanding the role and placement of K cells and L cells enhances knowledge about how the intestinal environment impacts various physiological responses, making their specific location in the crypts of Lieberkühn vital.