Which nerve carries parasympathetic innervation to the bladder?

The pelvic nerve is responsible for carrying parasympathetic innervation to the bladder. This nerve originates from the sacral segments of the spinal cord (S2-S4) and is specifically involved in regulating bladder function. When stimulated, the pelvic nerve promotes contraction of the bladder detrusor muscle, facilitating urination by allowing the bladder to fill and then empty appropriately.

The vagus nerve primarily provides parasympathetic innervation to the thoracic and abdominal organs, but it does not innervate the bladder. The phrenic nerve is predominantly responsible for motor control of the diaphragm, which is essential for breathing, and does not play a role in bladder innervation. The splanchnic nerves carry sympathetic fibers and are involved in the regulation of visceral organs, but they do not provide the parasympathetic control necessary for bladder function. Therefore, the pelvic nerve is crucial for the parasympathetic control of the bladder, making it the correct answer.