Na⁺ reabsorption A) uses 80% of the energy requirement of the kidney B) is under control of the hormone aldosterone in the distal portions of the nephron C) is linked to the reabsorption of water, Cl^-, glucose, amino acids, and urea D) requires that tubule cells expend energy E) all of these

Question

Quizplus · Accepted Answer

Na+ reabsorption in the nephron requires the active transport of ions across the tubule epithelium against a concentration gradient. This process is energy-intensive and accounts for about 80% of the energy requirement of the kidney. The hormone aldosterone regulates Na+ reabsorption and promotes its uptake in the distal portions of the nephron. Na+ reabsorption is linked to the reabsorption of other substances such as water, Cl-, glucose, amino acids, and urea through the creation of a concentration gradient. The process of active transport also requires energy expenditure by the tubule cells. Therefore, all of the given options are correct.

Na+ Reabsorption

Na⁺ Reabsorption