Blood vessel draining the glomerulus in a mammalian nephron is called

Options

A. renal artery and is wider than the vessel entering it
B. afferent arteriole and is wider than the vessel entering it
C. efferent venule and is narrower than the vessel entering it
D. efferent arteriole and is narrower than the vessel entering it

Answer

To answer the question "Blood vessel draining the glomerulus in a mammalian nephron is called," we can follow these steps:

### Step-by-Step Solution:

1. **Understand the Structure of the Nephron**:
- The nephron is the functional unit of the kidney. It consists of several parts, including the glomerulus, Bowman's capsule, and various tubules.

2. **Identify the Glomerulus**:
- The glomerulus is a network of capillaries where blood filtration occurs. It is surrounded by Bowman's capsule.

3. **Blood Flow into and out of the Glomerulus**:
- Blood enters the glomerulus through a vessel called the afferent arteriole.
- After filtration, the blood exits the glomerulus through another vessel.

4. **Determine the Correct Vessel**:
- The vessel that drains the glomerulus is called the efferent arteriole. This vessel is narrower than the afferent arteriole, which helps maintain a high filtration pressure within the glomerulus.

5. **Evaluate the Options**:
- Renal artery: This is incorrect as it supplies blood to the kidney, not draining it.
- Afferent arteriole: This is incorrect as it brings blood into the glomerulus.
- Efferent venule: This is incorrect as it is not the correct term for the vessel draining the glomerulus.
- Efferent arteriole: This is the correct answer as it is the vessel that drains the glomerulus.

### Final Answer:
The blood vessel draining the glomerulus in a mammalian nephron is called the **efferent arteriole**.

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