Manitoba Nephrology Nurse Practice Test

What regulates pH, potassium, sodium, and calcium in the nephron?

1. Afferent arterioles

2. Distal convoluted tubule

3. Collecting duct

4. Proximal convoluted tubule

The correct answer is: Distal convoluted tubule

The distal convoluted tubule plays a crucial role in the regulation of pH, potassium, sodium, and calcium in the nephron, making it the correct answer. This segment of the nephron is strategically located after the loop of Henle and before the collecting duct, and it is primarily responsible for the fine-tuning of electrolyte balance and acid-base homeostasis. Specifically, the distal convoluted tubule is where the reabsorption and secretion of important ions occur under the influence of hormonal regulation. For example, aldosterone increases sodium reabsorption and potassium secretion, while parathyroid hormone regulates calcium reabsorption. Additionally, bicarbonate can be secreted to help manage pH levels in the body. This targeted regulatory function helps maintain the overall electrolyte balance and pH, which are vital for proper bodily functions. Understanding the role of the distal convoluted tubule in these processes highlights its significance in nephrology and offers insight into how kidney function affects overall health.