Atrial Natriuretic Factor (ANF)

Options

A. causes vasodilation
B. increases blood pressure
C. decreases GFR
D. activates renin

Answer

### Step-by-Step Solution for Atrial Natriuretic Factor (ANF)

1. **Understanding Atrial Natriuretic Factor (ANF)**:
- ANF is a hormone produced by the heart's atria in response to atrial stretch. It plays a crucial role in regulating blood pressure and fluid balance.

2. **Functions of ANF**:
- **Causes Atrial Stretch**: The release of ANF is triggered by an increase in blood volume, which stretches the atrial walls.
- **Vasodilation**: ANF promotes the dilation of blood vessels. This process helps to lower blood pressure by reducing vascular resistance.
- **Decreases Blood Pressure**: Due to vasodilation, ANF effectively decreases blood pressure.
- **Increases Glomerular Filtration Rate (GFR)**: ANF enhances the GFR in the kidneys, promoting the excretion of sodium and water, which further aids in reducing blood volume and pressure.
- **Renal Inhibition**: ANF inhibits the renin-angiotensin-aldosterone system (RAAS), which is responsible for increasing blood pressure and fluid retention.
- **Cardiac Load Reduction**: By decreasing blood volume and pressure, ANF reduces the workload on the heart.

3. **Evaluating the Options**:
- **Causes Vasodilation**: True. ANF causes vasodilation, which lowers blood pressure.
- **Increases Blood Pressure**: False. ANF decreases blood pressure.
- **Decreases GFR**: False. ANF increases GFR.
- **Activates Renin**: False. ANF inhibits renin secretion.

4. **Conclusion**:
- The only correct statement regarding the function of Atrial Natriuretic Factor (ANF) is that it causes vasodilation.

### Final Answer:
The correct answer is that Atrial Natriuretic Factor (ANF) **causes vasodilation**.

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