Question

Which of the following guards the opening of hepatopancreatic duct into duodenum?
A) Semilunar valve
B) Ileocaecal valve
C) Pyloric sphincter
D) Sphincter of oddi

Answer 1

Hint: Firstly,let us understand what is hepatopancreatic duct. The association of common bile duct and pancreatic duct leads to the formation of hepatopancreatic duct. It is also known as hepatopancreatic ampulla or the ampulla of Vater.

Complete answer:
The starting part of the small intestine is called duodenum which lies between the small intestine and stomach. The partially digested food that enters duodenum mixes with the bile juice and other juices from the pancreas for complete digestion.
A) Semilunar valve: The semilunar valves are present between the outflow vessels and ventricles. They remain closed at the beginning of ventricular relaxation (diastole), that produce the second heart sounds. There are two semilunar valves. They are pulmonary valves and aortic valves.
B) Ileocaecal valve: It is located in the lower right portion of the abdomen. It is a type of sphincter muscle that forms the junction between ileum and colon. It facilitates the transport of digested food from the small intestine to large intestine.
C) Pyloric sphincter: It is a chain of smooth muscles that is located in between the stomach and small intestine. It acts like a valve to control the flow of stomach juices and partially digested food to duodenum from pylorus.
D) Sphincter of oddi(SO): It is a muscular valve that allows pancreatic juice and bile juice to flow between the small intestine and pancreas through hepatopancreatic duct.

Therefore the correct answer is (D) Sphincter of oddi.

Note:The inability of the sphincter muscles to relax and contract leads to the Sphincter of oddi dysfunction. The pain symptoms of having bile duct stones and gallstones is similar to the pain symptoms of the SO dysfunction.