In the urinary system, the structural and functional units of the kidney are called what?

• A. Villi
• B. Nephrons
• C. Alveoli
• D. Neurons

Answer: (B)

Verified step by step guidance

1. Understand that the question asks for the name of the structural and functional units of the kidney within the urinary system.
2. Recall that the kidney is composed of many microscopic units responsible for filtering blood and forming urine.
3. Identify that 'villi' are finger-like projections found in the small intestine, not related to the kidney.
4. Recognize that 'alveoli' are tiny air sacs in the lungs, involved in gas exchange, not kidney function.
5. Know that 'neurons' are nerve cells, which are part of the nervous system, not the urinary system; therefore, the correct term for the kidney's functional units is 'nephrons'.