Where counter-current mechanism operates in nephron?

Explanation

### Step-by-Step Solution:

1. **Understanding the Counter-Current Mechanism**:
- The counter-current mechanism is a physiological process that helps in the concentration of urine. It involves the interaction between two fluid flows that move in opposite directions.

2. **Identifying the Key Components**:
- The two main components involved in the counter-current mechanism are the **Loop of Henle** (part of the nephron) and the **Vasa Recta** (a capillary network surrounding the nephron).

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