Louder sound of heart beat occurs during closure of

Options

A. Tricuspid valve
B. Auriculo-ventricular valves
C. Mitral valve
D. Semilunar valves

Answer

To answer the question regarding the louder sound of the heartbeat, we can break it down into the following steps:

### Step-by-Step Solution:

1. **Understanding Heart Sounds**: The heart produces two primary sounds during its cycle, known as S1 and S2. These sounds are commonly referred to as "lub" and "dub".

2. **Identifying the Sounds**:
- **S1 (Lub)**: This sound occurs when the atrioventricular (A-V) valves close. It is characterized by lower intensity and longer duration.
- **S2 (Dub)**: This sound occurs when the semilunar valves close. It is characterized by higher intensity and shorter duration.

3. **Comparing the Sounds**:
- The S1 sound (lub) is softer and lasts longer compared to the S2 sound (dub), which is louder and shorter.

4. **Determining the Louder Sound**: Since the question asks for the louder sound of the heartbeat, we focus on the S2 sound, which is produced by the closure of the semilunar valves.

5. **Conclusion**: Therefore, the louder sound of the heartbeat occurs during the closure of the semilunar valves.

### Final Answer:
The louder sound of the heartbeat occurs during the closure of the semilunar valves.

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