As filtrate passes through the long loop of Henle, salt is removed and concentrated in the interstitial fluid of the kidney medulla. Because of this high salt concentration, the nephron is able to __________.

• A. excrete the maximum amount of salt
• B. neutralize toxins that might accumulate in the kidney
• C. control the pH of the interstitial fluid
• D. excrete a large amount of water
• E. establish a hyperosmotic interstitial medullary concentration

Answer: (E)

Verified step by step guidance

1. Understand the function of the loop of Henle: The loop of Henle is a part of the nephron in the kidney that plays a crucial role in concentrating urine and conserving water.
2. Recognize the role of salt concentration: As filtrate passes through the loop of Henle, salt is actively transported out of the filtrate and into the interstitial fluid of the kidney medulla, creating a high salt concentration.
3. Identify the effect of high salt concentration: The high salt concentration in the interstitial fluid allows the nephron to establish a hyperosmotic environment, which is essential for water reabsorption.
4. Consider the options provided: Evaluate each option based on the function of the loop of Henle and the effect of the high salt concentration.
5. Select the correct answer: The high salt concentration in the medulla allows the nephron to establish a hyperosmotic interstitial medullary concentration, which is crucial for the kidney's ability to concentrate urine and conserve water.