In human kidney, the blood vessel which is not a portal vein but starts with blood capillaries and end with blood capillaries is

Options

A. afferent arteriole
B. renal vein
C. renal artery
D. efferent arteriole

Answer

To solve the question, "In human kidney, the blood vessel which is not a portal vein but starts with blood capillaries and ends with blood capillaries is," we can follow these steps:

### Step-by-Step Solution:

1. **Understand the Definition of Portal Veins**:
- A portal vein is a type of blood vessel that starts and ends with capillaries. It carries blood from one capillary bed to another without passing through the heart.

2. **Identify Blood Vessels in the Kidney**:
- In the human kidney, the primary blood vessels include the renal artery, renal vein, afferent arterioles, and efferent arterioles.

3. **Analyze Each Option**:
- **Renal Artery**: This vessel carries oxygenated blood from the heart to the kidneys. It does not start and end with capillaries; it starts from the aorta and ends in arterioles.
- **Renal Vein**: This vessel carries deoxygenated blood away from the kidneys to the heart. It also does not start and end with capillaries; it starts from venules and ends in the inferior vena cava.
- **Afferent Arteriole**: This vessel carries blood into the glomerulus, which is a network of capillaries. It starts from the interlobular arteries and ends in the glomerular capillaries.
- **Efferent Arteriole**: This vessel carries blood away from the glomerulus and leads to peritubular capillaries. It also starts and ends with capillaries.

4. **Identify the Correct Answer**:
- The only vessel that starts with capillaries and ends with capillaries is the **efferent arteriole**. It connects the glomerular capillaries to the peritubular capillaries, making it the correct answer.

5. **Final Answer**:
- The blood vessel in the human kidney that is not a portal vein but starts and ends with blood capillaries is the **efferent arteriole**.