Cardiac sphincter muscle is a circular band of

Options

A. Striated muscles
B. Smooth muscles
C. Cardiac muscles
D. All the above .

Answer

**Step-by-Step Solution:**

1. **Understanding the Cardiac Sphincter Muscle:**
- The cardiac sphincter, also known as the lower esophageal sphincter, is a muscle located at the junction of the esophagus and the stomach.

2. **Type of Muscle:**
- The cardiac sphincter is classified as an involuntary muscle. Involuntary muscles are those that are not under conscious control.

3. **Composition of the Cardiac Sphincter:**
- The cardiac sphincter is specifically made up of smooth muscle tissue. Smooth muscles are non-striated and are found in various internal organs.

4. **Function of the Cardiac Sphincter:**
- Its primary function is to prevent the backflow of stomach contents, including acidic gastric juices, into the esophagus. This helps to protect the esophagus from damage due to acid.

5. **Identifying the Correct Answer:**
- Given the options, the correct answer is that the cardiac sphincter muscle is a circular band of **smooth muscles**.

**Final Answer:**
The cardiac sphincter muscle is a circular band of **smooth muscles**.

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