Cardiac sphincter is -

Options

A. Gastro-oesophageal sphincter
B. Gastro-duodenal sphincter
C. Pyloric sphincter
D. None

Answer

**Step-by-Step Solution:**

1. **Understanding the Cardiac Sphincter**: The cardiac sphincter is a muscle that is located at the junction of the esophagus and the stomach. It plays a crucial role in controlling the passage of food from the esophagus into the stomach.

2. **Identifying the Options**: The options provided are:
- Gastroesophageal sphincter
- Gastrodurinal sphincter
- Pyloric sphincter
- None of the above

3. **Analyzing the Function**: The primary function of the cardiac sphincter (or gastroesophageal sphincter) is to prevent the backflow of stomach contents into the esophagus, which can lead to conditions like acid reflux.

4. **Recognizing the Terminology**: The term "cardiac sphincter" is often used interchangeably with "gastroesophageal sphincter." The name "cardiac" is derived from the anatomical region of the stomach known as the cardiac portion, which is located near the esophagus.

5. **Conclusion**: Based on the analysis, the correct answer to the question "Cardiac sphincter is" is the first option: Gastroesophageal sphincter.

**Final Answer**: Cardiac sphincter is the Gastroesophageal sphincter.

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