What primary function does the stomach serve in digestion?

The stomach plays a critical role in digestion primarily by mixing and storing food. When food enters the stomach, it undergoes mechanical and chemical processing. The muscular walls of the stomach contract to mix the food with gastric juices, which contain enzymes and acids necessary for breaking down the food into a semi-liquid form called chyme. This mixing is essential for ensuring that the food is adequately digested before it moves on to the small intestine, where nutrient absorption occurs. Additionally, the stomach serves as a temporary storage area, allowing for gradual release of chyme into the small intestine, optimizing the digestive process. This function distinguishes it from other organs in the digestive system, particularly those focused on nutrient absorption or temperature regulation.