In the context of the nephron, the functional unit of a kidney is a(n):

• A. Renal pelvis
• B. Nephron
• C. Ureter
• D. Renal pyramid

Answer: (B)

Verified step by step guidance

1. Step 1: Understand the structure and function of the kidney. The kidney is composed of several parts, including the renal pelvis, ureter, renal pyramids, and nephrons.
2. Step 2: Define the nephron. The nephron is the microscopic functional unit of the kidney responsible for filtering blood and forming urine.
3. Step 3: Differentiate the nephron from other kidney structures. The renal pelvis is a funnel-shaped structure that collects urine, the ureter transports urine to the bladder, and the renal pyramids are cone-shaped tissues containing many nephrons.
4. Step 4: Recognize that the nephron performs the essential functions of filtration, reabsorption, and secretion, which are critical for maintaining fluid and electrolyte balance.
5. Step 5: Conclude that the nephron is the correct answer because it is the fundamental functional unit of the kidney, unlike the other structures which serve as conduits or tissue groupings.