All of the following are true about actions of - ANF except

Options

A. decreased blood pressure
B. causes vasoconstriction
C. decreased sodium reabsorption
D. increased sodium excretion

Answer

**Step-by-Step Solution:**

1. **Understanding ANF**: Atrial Natriuretic Factor (ANF) is a peptide hormone secreted by the cardiac atria. Its primary role is to regulate blood pressure and fluid balance in the body.

2. **Functions of ANF**:
- **Increased Sodium Excretion**: ANF promotes the excretion of sodium by the kidneys, which helps in reducing blood volume and blood pressure.
- **Decreased Sodium Reabsorption**: It inhibits sodium reabsorption in the renal tubules, further contributing to increased sodium excretion.
- **Decreased Blood Pressure**: ANF acts to lower blood pressure by promoting vasodilation and reducing blood volume.

3. **Identifying the Exception**: The question asks for the statement that is NOT true about the actions of ANF. The options likely include:
- Decreased blood pressure
- Increased sodium excretion
- Decreased sodium reabsorption
- **Vasoconstriction** (this is the odd one out)

4. **Analyzing Vasoconstriction**: Vasoconstriction refers to the narrowing of blood vessels, which typically results in increased blood pressure. Since ANF is known to decrease blood pressure, it does not cause vasoconstriction.

5. **Conclusion**: Therefore, the statement that ANF causes vasoconstriction is incorrect. The correct answer is that ANF does not cause vasoconstriction.

**Final Answer**: ANF does not cause vasoconstriction.

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