Valvulae conniventes, also known as plicae circulares and Kerckring folds, are folds found in the small intestine. These folds consist of mucosal layer. The number of valvulae conniventes decreases with the progression of small intestine from duodenum to ileum i.e., the mucosal folds are largest and thickest in duodenum whereas in distal ileum, these mucosal folds disappear. Reference: https://radiopaedia.org/articles/valvulae-conniventes Image via: https://radiopaedia.org/articles/valvulae-conniventes