Where is intrinsic factor secreted from?

Intrinsic factor is a glycoprotein that plays a critical role in the absorption of vitamin B12 from the gastrointestinal tract. It is secreted specifically by the parietal cells located in the fundus of the stomach. This secretion is essential because vitamin B12 is necessary for red blood cell formation and neurological function.

The fundus of the stomach is the upper part that serves as a storage area and contains the parietal cells responsible for producing gastric acid and intrinsic factor. When food enters the stomach, these cells are stimulated to release intrinsic factor along with hydrochloric acid, creating the acidic environment needed for digestion and facilitating the absorption of vitamin B12 in the later parts of the intestine.

In contrast, other locations mentioned, such as the duodenum, pyloric region, and pancreas, do not produce intrinsic factor. The duodenum is primarily involved in the initial stages of digestion following gastric secretions, while the pyloric region and pancreas have roles in regulating the flow of digested materials and producing digestive enzymes, respectively, but do not secrete intrinsic factor. Thus, the correct understanding is firmly aligned with the role of the fundus of the stomach in intrinsic factor production.