Brunner's glands are a group of glands within the duodenum. Until the 70s of the 20th century, they were called “duodenal glands,” but now the term “Brunner’s gland” has taken hold among researchers and doctors. If you look at the anatomy picture of the gland, it seems that this is some kind of unusual organ located at the very end of the stomach. I'm not that smart, so I'll state the essence of the issue in the format of notes, but in my own words.
If you don't have access to anatomy pictures on the Internet, I can describe what you saw using only such cliches as the duodenal duct and duodenum. Imagine a narrowed duodenal tube, and then you will more or less understand the principle of its operation. If you can imagine it, of course. The duodenum is similar to a crescent, which starts from the place where the bile duct enters it and ends with a sphincter located at a height of approximately 50 cm from the beginning of the stomach. The length of the entire intestine is about 40 cm. The upper half of the intestine is called the “villous section” because it has villi located deep under the mucous membrane and villi of the same gland located next to them. These villi rise and form a kind of “jagged edge” of the intestine. There, fluids with pancreatic enzymes, electrolytes, and nutrients are absorbed. Next there are two glands: a large duo