**Question:** Each kidney contains about ___nephrons: (Repeat)

A. 300,000
B. 1,000,000
C. 1,000,000
D. 1,200,000

**Core Concept:** Nephrons are the functional units of the kidney responsible for filtering blood, maintaining electrolyte balance, and producing urine.

**Why the Correct Answer is Right:** The correct answer is **D. 1,200,000**, as this represents the approximate number of nephrons found in each kidney. Nephrons are the basic functional units of the kidney, responsible for filtering blood, regulating electrolyte balance, and producing urine. This number is important for understanding the kidney's capacity to perform these vital functions.

**Why Each Wrong Option is Incorrect:**

A. **300,000**: This is significantly lower than the actual number of nephrons in the kidney, making it incorrect.
B. **1,000,000**: This is also higher than the actual number of nephrons, making it incorrect as well.
C. **1,000,000**: Similar to options A and B, this number is too high, making it incorrect.

**Why Each Wrong Option is Incorrect:**

A. **300,000**: This is significantly lower than the actual number of nephrons in the kidney, making it incorrect.
B. **1,000,000**: This is also higher than the actual number of nephrons, making it incorrect as well.
C. **1,000,000**: Similar to options A and B, this number is too high, making it incorrect.

**Clinical Pearl:** Understanding the number of nephrons in the kidney is crucial for grasping its capacity to filter blood, maintain electrolyte balance, and produce urine. This information is essential for medical students, residents, and practitioners alike, as it relates to the kidney's function and overall health assessment.

**Correct Answer Explanation:** The correct answer, **D. 1,200,000**, represents the approximate number of nephrons found in the human kidney. Nephrons are the functional units of the kidney responsible for filtering blood, regulating electrolyte balance, and producing urine. This number is essential for understanding the kidney's capacity to perform these crucial functions and maintaining overall kidney health.

**Why Each Wrong Option is Incorrect:**

A. **300,000**: This is significantly lower than the actual number of nephrons in the kidney, making it incorrect.
B. **1,000,000**: This is also higher than the actual number of nephrons, making it incorrect.
C. **1,000,000**: Similar to options A and B, this number is too high, making it incorrect.

**Clinical Pearl:** Understanding the number of nephrons in the kidney is crucial for medical students, residents, and practitioners alike, as it relates to the