Atrial wall of the heart muscle secrete's a peptide hormone to reduce the blood pressure is:

Options

A. Cholycystokinin
B. Erythropoetin
C. Atrial natriuretic factor
D. Epinephrine

Answer

To answer the question regarding the peptide hormone secreted by the atrial wall of the heart muscle that reduces blood pressure, we can follow these steps:

### Step-by-Step Solution:

1. **Identify the Source**: The question specifies that the hormone is secreted by the atrial wall of the heart. The atria are the upper chambers of the heart.

2. **Understand the Function**: The hormone in question is responsible for reducing blood pressure. This indicates that it plays a role in the regulation of blood volume and vascular resistance.

3. **Consider the Options**: The options provided are:
- Cholecystokinin
- Erythropoietin
- Atrial Natriuretic Factor (ANF)
- Epinephrine

4. **Evaluate Each Option**:
- **Cholecystokinin**: This hormone is produced in the gastrointestinal tract and is involved in digestion, not blood pressure regulation. So, this option is incorrect.
- **Erythropoietin**: This hormone is secreted by the kidneys and is primarily involved in the production of red blood cells, not in reducing blood pressure. Therefore, this option is also incorrect.
- **Atrial Natriuretic Factor (ANF)**: This is a peptide hormone secreted by the atrial walls of the heart. It helps to lower blood pressure by promoting vasodilation and increasing sodium excretion in the urine. This option is correct.
- **Epinephrine**: This hormone is secreted by the adrenal glands and is involved in the fight-or-flight response, which generally increases blood pressure rather than reducing it. Thus, this option is incorrect.

5. **Conclusion**: Based on the evaluation of the options, the correct answer is **Atrial Natriuretic Factor (ANF)**, as it is the peptide hormone secreted by the atrial wall of the heart that functions to reduce blood pressure.

### Final Answer:
The peptide hormone secreted by the atrial wall of the heart muscle to reduce blood pressure is **Atrial Natriuretic Factor (ANF)**.

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