Statement-1: Small amount of urea enters the thick segment of Henle's loop which is tranported back to interstitium by collecting tubules.
Statement-2: Collecting tubules and thick segment of Henle's loop are permeable to urea.

Options

A. both statements 1 and 2 are correct.
B. Statement 1 is correct but statement 2 is incorrect
C. Statement 1 is incorrect but statement 2 is correct
D. Both statements 1 and 2 are incorrect.

Explanation

To analyze the statements provided, we will evaluate each one based on our understanding of the nephron's structure and function, particularly focusing on the loop of Henle and collecting tubules.

### Step-by-Step Solution:

1. **Understanding Statement-1**:
- The statement claims that a small amount of urea enters the thick segment of Henle's loop and is transported back to the interstitium by collecting tubules.
- In reality, urea does diffuse into the medullary interstitial fluid from the collecting ducts, but it does not get actively transported back into the interstitium from the thick segment of Henle's loop. Instead, it is primarily the thin segment of the loop that allows for some passive diffusion of urea. Therefore, this statement is **false**.

2. **Understanding Statement-2**:
- This statement asserts that the collecting tubules and the thick segment of Henle's loop are permeable to urea.
- The thick segment of the loop of Henle, along with the distal tubule and cortical collecting tubules, are generally considered to be relatively impermeable to urea. While some urea reabsorption can occur, it is minimal. Thus, this statement is also **false**.

3. **Conclusion**:
- Both statements are false. The first statement incorrectly describes the transport of urea, and the second statement incorrectly states the permeability of the thick segment of Henle's loop and collecting tubules to urea.

### Final Answer:
Both Statement-1 and Statement-2 are false.

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