This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Anatomy
[{'content': 'The Sphincter of Oddi consists of: \nSelect and explain. \nA. 2 sphincters, B. 3 sphincters, C. 4 sphincters, D. 5 sphincters', 'role': 'user'}, {'content': 'Answer: B \nExplanation: The Sphincter of Oddi is a muscular valve that controls the flow of digestive juices (bile and pancreatic juice) through the ampulla of Vater into the second pa of the duodenum. It is 10 - 15 mm in length, situated within muscular layer of media in the duodenum.It consists of sphincters at 3 levels: 1. Sphincter choledochus: covers the distal end of intraduodenal pa pa of common bile duct before it joins with the pancreatic duct of Wirsung. 2. Sphincter pancreaticus: located at the distal end of pancreatic duct. 3. Ampullary sphincter: covers the distal end of both the ducts after they unite to form a single common channel that opens into the duodenal lumen at an elevation called Ampulla of Vater.', 'role': 'assistant'}]