The site of origin of the preganglionic fibers of the parasympathetic nervous system is the
A) thoracolumbar region of the spinal cord.
B) higher brain centers.
C) chain and prevertebral ganglia.
D) brain stem and the sacral region of the cord.

Question

Quizplus · Accepted Answer

The site of origin of the preganglionic fibers of the parasympathetic nervous system is the brain stem and the sacral region of the spinal cord. This is why the parasympathetic nervous system is also referred to as the craniosacral division. The cranial nerves III, VII, IX, and X carry parasympathetic fibers from the brain stem to specific organs, while the sacral nerves carry parasympathetic fibers to the colon, bladder, and reproductive organs.

The Site of Origin of the Preganglionic Fibers of the Parasympathetic