Which of the following are not associated with the mucosa of the small intestine?

Brunner’s glands are located in the submucosa of the duodenum (not mucosa). All others are associated with the mucosa of the small intestine. Plicae circulars (valves of Kerckring, or valvulae conniventes) are the circular folds of the small intestine. They enhance absorption by increasing surface area. Villi and microvilli also increase the surface area of the small intestine. Crypts of Lieberkuhn are the intestinal glands.