Kaplan Nursing Entrance Practice Exam

What is an associated function of the kidneys aside from urine formation?

1. Regulating blood sugar levels

2. Regulating volume and salt content of fluids

3. Producing red blood cells

4. Releasing bile for digestion

The correct answer is: Regulating volume and salt content of fluids

The correct choice highlights the kidneys' critical role in maintaining homeostasis within the body through the regulation of fluid volume and electrolyte balance, particularly sodium. The kidneys achieve this by filtering blood, reabsorbing necessary substances, and excreting waste materials, which includes managing the amount of water and salts excreted in urine. This function is vital for maintaining blood pressure, as well as the proper functioning of muscles and nerves, as both are influenced by electrolyte levels. The other options, while related to various body functions, do not accurately reflect a primary role of the kidneys. For instance, regulating blood sugar levels is primarily a function of the pancreas. The production of red blood cells is influenced by the hormone erythropoietin, which the kidneys do produce, but it is not the kidneys' primary function. Releasing bile for digestion is solely the function of the liver and is not associated with the kidneys at all. Thus, the emphasis on the kidneys' regulatory functions regarding fluid and salt content is what makes this choice the most accurate reflection of their associated functions beyond urine formation.