A muscular sphincter regulating opening of oesophagus into the stomach is called -

Options

A. Pyloric sphincter
B. Cardiac Sphincter
C. Sphincter of oddi
D. Boyden sphincter

Answer

To answer the question regarding the muscular sphincter that regulates the opening of the esophagus into the stomach, we can follow these steps:

1. **Identify the Structure**: The question asks for a specific muscular sphincter that controls the opening between the esophagus and the stomach.

2. **Understand the Anatomy**: The esophagus connects to the stomach at a specific point. This point is crucial for the passage of food from the esophagus into the stomach.

3. **Recognize the Function**: The sphincter functions as a valve, controlling the entry of food into the stomach and preventing the backflow of stomach contents into the esophagus.

4. **Name the Sphincter**: The muscular sphincter that regulates this opening is known as the gastroesophageal sphincter. It is also commonly referred to as the cardiac sphincter.

5. **Select the Correct Answer**: Based on the information, the correct answer to the question is the cardiac sphincter.

### Final Answer:
The muscular sphincter regulating the opening of the esophagus into the stomach is called the **cardiac sphincter** (or gastroesophageal sphincter).