What do rugae do in the stomach?

Rugae are the folds found in the lining of the stomach that allow it to expand when food enters. When the stomach is empty, these folds are tightly packed together, creating a smaller volume. When food is consumed, the stomach fills and the rugae flatten out, enabling the organ to stretch and accommodate the increased volume. This ability to expand is essential for the storage and gradual digestion of food, as the stomach can hold a significant amount of material. This function also plays a role in mixing food with gastric juices for optimal digestion.