In the urinary system, the functional unit of the kidney is the:

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

Answer: (B)

Verified step by step guidance

1. Understand that the question asks for the functional unit of the kidney, which means the smallest structure capable of performing all the kidney's functions.
2. Recall that the kidney's main functions include filtering blood, removing waste, and regulating fluid and electrolyte balance.
3. Identify the nephron as the microscopic structure responsible for these functions, including filtration, reabsorption, and secretion.
4. Recognize that other options like the ureter, renal pyramid, and glomerulus are parts of the urinary system or kidney anatomy but do not independently perform all kidney functions.
5. Conclude that the nephron is the correct answer because it is the complete functional unit of the kidney.