A nurse is caring for a client who has a serum potassium level of 3.1 mEq/L. Which part of the nephron is primarily responsible for potassium reabsorption?

• A. Bowman's capsule
• B. Glomerulus
• C. Collecting duct
• D. Proximal convoluted tubule

Answer: (D)

Verified step by step guidance

1. Understand the role of potassium in the body: Potassium is a vital electrolyte that helps regulate nerve function, muscle contraction, and fluid balance. A serum potassium level of 3.1 mEq/L indicates hypokalemia (low potassium levels).
2. Review the anatomy of the nephron: The nephron is the functional unit of the kidney, responsible for filtering blood and forming urine. It consists of several parts, including Bowman's capsule, the glomerulus, the proximal convoluted tubule, the loop of Henle, the distal convoluted tubule, and the collecting duct.
3. Identify the function of each nephron part: Bowman's capsule and the glomerulus are involved in filtration, not reabsorption. The collecting duct is primarily responsible for water reabsorption and fine-tuning electrolyte balance. The proximal convoluted tubule is the main site for reabsorption of potassium, sodium, glucose, and other substances.
4. Explain potassium reabsorption: Potassium reabsorption occurs primarily in the proximal convoluted tubule through active and passive transport mechanisms. This ensures that potassium is retained in the body to maintain proper electrolyte balance.
5. Conclude the reasoning: Based on the nephron's structure and function, the proximal convoluted tubule is the correct answer because it is the primary site for potassium reabsorption, as opposed to Bowman's capsule, the glomerulus, or the collecting duct.