Which blood vessel takes blood away from kidney ?

Options

A. Renal portal vein
B. Renal vein
C. Afferent arteriole
D. Efferent arteriole

Answer

To determine which blood vessel takes blood away from the kidney, we can follow these steps:

### Step-by-Step Solution:

1. **Identify the Function of the Kidneys**:
- The kidneys are responsible for filtering blood to remove waste products and excess substances, thus purifying the blood.

2. **Understand Blood Flow in the Kidneys**:
- Blood enters the kidneys through the renal artery, which carries impure blood (blood containing waste products).
- After filtration, the purified blood exits the kidneys.

3. **Identify the Blood Vessel that Exits the Kidney**:
- The blood vessel that takes the purified blood away from the kidneys is known as the renal vein.

4. **Differentiate Between Related Blood Vessels**:
- The renal portal vein is not the correct answer as it is involved in a different system (the portal system).
- Afferent arterioles bring blood to the glomerulus, while efferent arterioles take blood away from the glomerulus, but they are not the main vessel that exits the kidney.

5. **Conclusion**:
- Therefore, the blood vessel that takes blood away from the kidney is the renal vein.

### Final Answer:
The blood vessel that takes blood away from the kidney is the **renal vein**.

---