Parasympathetic innervation to the lower ureters is provided by which spinal levels?

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

Answer: (C)

Parasympathetic input to the lower ureter comes from the pelvic splanchnic nerves, which originate from the sacral spinal segments S2–S4. These preganglionic fibers travel in the pelvic nerves and contribute to the inferior hypogastric (pelvic) plexus to reach the distal ureter, where they synapse in the plexus or in the ureter wall. Postganglionic fibers then promote peristalsis of the lower ureter to help move urine toward the bladder. The vagus nerve supplies parasympathetic fibers to many upper abdominal organs, not the lower ureter, and the thoracolumbar outflow (T10–L2 or T9–11) provides sympathetic innervation, not parasympathetic.