Anatomy Brunner’s glands secrete an alkaline product that helps achieve optimal pH for the activity of pancreatic enzymes. Where are these glands located? A At the base of villi throughout the small intestine B In the epithelium of the ampulla of Vater C In the mucosa and submucosa of the jejunum D In the submucosa of the duodenum 💡 Explanation Brunner's glands secrete an alkaline product that helps achieve optimal pH for the activity of pancreatic enzymes. Where are these glands located? ✓ Correct Answer: D. In the submucosa of the duodenum