Fill in the Blank QuestionFill in the blank question.Internally, the stomach lining is composed of numerous folds or rugae.

The blank can be filled with "rugae."

Explanation:

The stomach lining has numerous folds that are referred to as rugae. These rugae allow the stomach to expand when food enters it, providing the necessary flexibility to accommodate different amounts of food. The presence of rugae is essential for the mechanical digestion of food as they increase the surface area available for gastric juices to act on the ingested food. When the stomach is empty, these folds are more pronounced, and as the stomach fills, the rugae flatten out, providing more room for the food to be processed effectively. This adaptation plays a crucial role in the digestive process, facilitating both storage and churning of food within the stomach.