The main organ involved in the digestion of food is the stomach. It plays a vital role in breaking down food into a semi-liquid substance through mechanical and chemical processes. The stomach secretes gastric juices that contain enzymes and acids, which aid in the digestion of proteins and kill harmful bacteria. This process prepares the food for further digestion and nutrient absorption in the small intestine. Studying stomach function is crucial in understanding gastrointestinal health and related disorders.