Answer
Rugae are folds are gastric folds in the walls of an empty stomach. As food enters the stomach, the rugae stretch and disappear as they make room for food.
Work Step by Step
Rugae involve both the mucosa and the submucosal layer of the stomach. These folds are clearly identifiable when the stomach is empty. However, as the food enters the stomach, and requires more room, the rugae stretch and eventually disappear to provide more room for the increasing volume of food that enters during a meal.
