Brunner's glands secrete an alkaline product that helps achieve optimal pH for the activity of pancreatic enzymes. Where are these glands located?
Brunner's glands are located in the submucosa of the duodenum. These glands are connected to the intestinal lumen by ducts that open into ceain crypts. They secrete an alkaline product that protects the duodenal mucosa from the acidic chyme and helps achieve optimal pH for pancreatic enzymes. The small intestinal villi are outgrowths of the mucosa into the lumen. Their epithelium contains columnar absorptive cells and goblet cells (produce acid glycoproteins that protect and lubricate the lining of the intestine). Near the base of each villus, there are tubular glands called crypts whose lining is continuous with the simple columnar epithelium of the villus. The crypts include Paneth cells, which produce acidophilic cytoplasmic granules containing bactericidal enzymes. The lamina propria of the small intestine penetrates the core of the villi and is composed of blood vessels, lymphatics, fibroblasts, and smooth muscle cells. The ampulla of Vater receives bile from the common bile duct and the main pancreatic duct, delivering it to the duodenum through the major duodenal papilla. The mucosa and submucosa of the jejunum are both included in the permanent folds called the plica circulares. Ref: Moon D.A., Foreman K.B., Albeine K.H. (2011). Chapter 10. Midgut and Hindgut. In D.A. Moon, K.B. Foreman, K.H. Albeine (Eds), The Big Picture: Gross Anatomy.
At the base of villi throughout the small intestine
In the epithelium of the ampulla of Vater
In the mucosa and submucosa of the jejunum
In the submucosa of the duodenum