Parasympathetic level of the kidneys.

• A. T10-L2
• B. S2-4 Pelvic Splanchnic
• C. T9-11
• D. C2-Vagus

Answer: (D)

Parasympathetic innervation to abdominal viscera, including the kidneys, comes from the vagus nerve. The vagus (cranial nerve X) carries preganglionic parasympathetic fibers that travel with the renal plexus to reach the kidney and modulate its function. The parasympathetic fibers originate in the brainstem and travel in CN X to innervate most thoracic and upper abdominal organs, unlike the pelvic parasympathetics from S2–S4 or the sympathetic fibers from T10–L2. The pelvic splanchnic nerves supply pelvic organs and hindgut, not the kidney, and thoracolumbar T10–L2 represents sympathetic input. Thus the kidney’s parasympathetic level is best represented by the vagus nerve.