In human beings which of the following opens into the duodenum

Options

A. Hepatic duct and pancreatic duct separately
B. Hepato-pancreatic duct
C. 1st hepatic duct, then pancreatic duct
D. 1st pancreatic duct then hepatic duct

Answer

To answer the question "In human beings, which of the following opens into the duodenum?", we will follow these steps:

### Step-by-Step Solution:

1. **Understand the Anatomy**: The duodenum is the first part of the small intestine that connects to the stomach. It plays a crucial role in digestion.

2. **Identify the Structures**: The question provides several options related to ducts that may open into the duodenum. The main ducts to consider are:
- Hepatic duct
- Pancreatic duct
- Common bile duct
- Hepato-pancreatic duct

3. **Function of the Liver and Pancreas**:
- The liver produces bile, which is transported via the hepatic duct.
- The pancreas produces digestive enzymes, which are transported via the pancreatic duct.

4. **Formation of the Common Bile Duct**:
- The hepatic duct carries bile from the liver to the gallbladder (via the cystic duct).
- The gallbladder releases bile into the common bile duct, which is formed when the cystic duct merges with the hepatic duct.

5. **Connection to the Pancreatic Duct**:
- The common bile duct merges with the pancreatic duct, forming the hepato-pancreatic duct.

6. **Opening into the Duodenum**:
- The hepato-pancreatic duct opens into the duodenum. This is the key point as it is the duct that carries both bile and pancreatic juices into the digestive tract.

7. **Conclusion**: Based on the above steps, the correct answer is that the **hepato-pancreatic duct** opens into the duodenum.

### Final Answer:
The hepato-pancreatic duct opens into the duodenum.