Select the incorrect statement about cortical nephrons.

Options

A. These are mainly concerned with urine concentration .
B. These have shorter of loop of Henle.
C. These do not have major role in Counter current mechanism.
D. These lack association with vasa recta .

Answer

To solve the question regarding the incorrect statement about cortical nephrons, we will analyze each of the provided options step by step.

### Step 1: Understand the structure and function of cortical nephrons
Cortical nephrons are one of the two main types of nephrons found in the kidneys (the other being juxtamedullary nephrons). They are primarily located in the renal cortex and have shorter loops of Henle that do not extend deep into the medulla.

**Hint:** Remember that cortical nephrons are primarily located in the renal cortex and have shorter loops of Henle.

### Step 2: Analyze the first option
**Option 1:** "These are mainly concerned with urine concentration."
- This statement is incorrect. Cortical nephrons are not primarily involved in urine concentration; that role is mainly fulfilled by juxtamedullary nephrons, which have longer loops of Henle and are associated with the counter-current mechanism.

**Hint:** Focus on the primary function of cortical nephrons versus juxtamedullary nephrons.

### Step 3: Analyze the second option
**Option 2:** "These are shorter of loop of Henle."
- This statement is correct. Cortical nephrons have shorter loops of Henle compared to juxtamedullary nephrons.

**Hint:** Recall the anatomical differences between cortical and juxtamedullary nephrons.

### Step 4: Analyze the third option
**Option 3:** "These do not have major role in counter current mechanism."
- This statement is also correct. Cortical nephrons do not play a significant role in the counter-current mechanism, which is primarily associated with juxtamedullary nephrons.

**Hint:** Consider the role of the counter-current mechanism in urine concentration.

### Step 5: Analyze the fourth option
**Option 4:** "These lack association with vasa recta."
- This statement is correct. Cortical nephrons do not have a significant association with vasa recta, which are blood vessels that surround the loops of Henle in juxtamedullary nephrons.

**Hint:** Think about the vascular structures associated with different types of nephrons.

### Conclusion
After analyzing all the options, the incorrect statement about cortical nephrons is:
- "These are mainly concerned with urine concentration."

### Final Answer
The incorrect statement about cortical nephrons is: **"These are mainly concerned with urine concentration."**