Function of SA node is

Options

A. Muscular pain
B. Contraction of lungs
C. Uricotelic
D. None of the above

Answer

### Step-by-Step Solution:

1. **Identify the Location and Structure of the SA Node**:
- The SA node, also known as the sinoatrial node, is located in the upper right corner of the right atrium of the heart, specifically in the inner wall called the myocardium.

2. **Understand the Function of the SA Node**:
- The primary function of the SA node is to generate electrical impulses that initiate the heartbeat. It is capable of creating action potentials without any external stimuli, which is why it is referred to as the natural pacemaker of the heart.

3. **Significance of the SA Node**:
- The SA node ensures a steady rhythm of the heart, maintaining a consistent heart rate. This is crucial for proper blood circulation throughout the body.

4. **Consider the Options Provided**:
- The options given are:
- a) Muscular pain
- b) Contraction of lungs
- c) Uricotelic
- d) None of the above

5. **Analyze Each Option**:
- **Muscular Pain**: While the SA node itself does not directly cause muscular pain, dysfunction of the SA node can lead to irregular heart rhythms, which may result in cardiac pain, often perceived as chest pain.
- **Contraction of Lungs**: This is unrelated to the function of the SA node, as lung contraction is controlled by different mechanisms (primarily the diaphragm and intercostal muscles).
- **Uricotelic**: This term refers to organisms that excrete uric acid, which has no connection to the function of the SA node.
- **None of the Above**: This option implies that none of the other answers are correct.

6. **Select the Correct Answer**:
- Given the analysis, the most relevant option is **muscular pain**, as it relates to the consequences of SA node dysfunction.

### Final Answer:
The function of the SA node is best represented by option a) Muscular pain.

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