Manitoba Nephrology Nurse Practice Test

What is the primary function of the Distal Convoluted Tubule?

1. Filtration

2. Concentration of urine

3. Regulation of electrolyte balance

4. Reabsorption of nutrients

The correct answer is: Regulation of electrolyte balance

The primary function of the Distal Convoluted Tubule (DCT) is the regulation of electrolyte balance. This section of the nephron plays a crucial role in fine-tuning the composition of urine by reabsorbing specific ions and substances, such as sodium and chloride, while also being involved in the secretion of potassium and hydrogen ions. The DCT's ability to adjust electrolyte levels helps maintain homeostasis in the body, particularly in relation to blood chemistry and pressure. In addition, the DCT responds to hormonal signals such as aldosterone, which promotes sodium reabsorption and potassium excretion, further emphasizing its role in regulating electrolytes. This balance is essential for various bodily functions, including fluid balance, pH regulation, and overall metabolic processes. While filtration primarily occurs in the glomerulus and reabsorption of nutrients takes place throughout different parts of the nephron, the unique focus of the DCT on electrolyte balance sets it apart as a critical player in kidney function.