What solutes contribute to the high osmotic pressure of interstitial fluid in the renal medulla?

Explanation

To answer the question about the solutes that contribute to the high osmotic pressure of interstitial fluid in the renal medulla, we can follow these steps:

### Step-by-Step Solution:

1. **Understanding the Renal Medulla**: The renal medulla is the innermost part of the kidney, which plays a crucial role in the concentration of urine and the regulation of water and solute balance in the body.

2. **Defining Interstitial Fluid**: Interstitial fluid is the fluid found in the spaces between cells. In the renal medulla, this fluid has a high osmotic pressure, which is essential for the kidney's ability to concentrate urine.

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