Which nervous system is involved in the urinary system?

• A. Sympathetic
• B. Parasympathetic
• C. Somatic
• D. Central

Answer: (B)

Parasympathetic control drives urination by stimulating the bladder’s detrusor muscle to contract. The pelvic nerves release acetylcholine onto muscarinic receptors on the detrusor, causing contraction and the urge to void. While the sympathetic system helps store urine by relaxing the detrusor and tightening the internal sphincter, and the somatic nerves control the external sphincter for voluntary control, the action that initiates emptying relies on parasympathetic input. Therefore, the parasympathetic system is the best answer.