The stomach is a key organ in the human digestive system responsible for the mechanical and chemical breakdown of food. It secretes gastric acid and enzymes, such as pepsin, which initiate protein digestion. The stomach’s muscular layers aid in mixing and propelling food toward the small intestine. Surgically, careful attention to the blood supply from the left and right gastric arteries is crucial to avoid ischemic complications. The stomach also serves as a reservoir, allowing controlled release of chyme into the duodenum. Unlike the lung, heart, or spleen, which have distinct functions in respiration, circulation, and immune response respectively, the stomach’s role is exclusively digestive.

Reference: Gray’s Anatomy, Henry Gray, 42nd Edition.