Final answer:
The pyloric sphincter is the structure that connects the stomach to the duodenum of the small intestine and regulates the passage of digested food.4) pyloric sphincter
Step-by-step explanation:
The structure that connects the stomach to the duodenum of the small intestine is the pyloric sphincter. The pyloric sphincter, a band of smooth muscle, is located at the junction between the stomach and the duodenum, specifically at the end of the pyloric canal. Its primary function is to control the emptying of the stomach contents into the duodenum, thereby regulating the process of digestion.