Hawaii Massage License Practice Exam

What is the functional unit of the kidney?

1. Glomerulus

2. Nephron

3. Renal cortex

4. Collecting duct

The correct answer is: Nephron

The nephron is the functional unit of the kidney because it is the primary structure responsible for filtering blood and forming urine. Each kidney contains around a million nephrons, which work individually to perform several essential functions, including the filtration of blood, reabsorption of essential nutrients and water, and the excretion of waste products. The nephron's structure includes several key components, such as the glomerulus, where the initial filtration occurs, and the renal tubule, which reabsorbs necessary substances and secretes waste. This intricate design allows the nephron to regulate water balance, electrolytes, and waste products effectively, demonstrating its critical role in maintaining homeostasis in the body. Other options, while related to kidney function, do not represent the functional unit. The glomerulus is a part of the nephron and is responsible for filtering blood, but it alone does not encompass all kidney functions. The renal cortex refers to the outer layer of the kidney where nephrons reside but is not a functional unit on its own. The collecting duct is involved in the final concentration of urine and is also a component of the nephron structure but does not function independently to filter blood or create urine. Therefore, the nephron is accurately identified as