In human being sphincter of Oddi is situated in:

Options

A. Common bile duct
B. Ampulla of vater
C. Main pancreatic duct
D. Common hapatic duct

Answer

**Step-by-Step Solution:**

1. **Understanding the Sphincter of Oddi**: The Sphincter of Oddi is a muscular valve that controls the flow of digestive juices (bile and pancreatic juice) from the liver and pancreas into the small intestine.

2. **Location of the Sphincter of Oddi**: It is located at the junction where the common bile duct and the pancreatic duct meet before they enter the duodenum (the first part of the small intestine).

3. **Identifying the Ducts**: The common bile duct carries bile from the liver and gallbladder, while the pancreatic duct carries pancreatic juices from the pancreas.

4. **Entering the Duodenum**: After the common bile duct and pancreatic duct merge, they enter the duodenum through an area known as the hepatopancreatic ampulla.

5. **Naming of the Ampulla**: The hepatopancreatic ampulla is also referred to as the Ampulla of Vater.

6. **Function of the Sphincter of Oddi**: The Sphincter of Oddi regulates the flow of bile and pancreatic juices into the duodenum, preventing backflow and ensuring proper digestion.

7. **Conclusion**: Therefore, the Sphincter of Oddi is situated in the hepatopancreatic ampulla (Ampulla of Vater).

8. **Final Answer**: The correct answer is that the Sphincter of Oddi is situated in the Ampulla of Vater.

---