Final answer:
The pre-ganglionic cell bodies of the parasympathetic nervous system are located in the brainstem and sacral spinal cord, also known as the craniosacral system.
Step-by-step explanation:
The pre-ganglionic cell bodies of the parasympathetic nervous system originate in the brainstem and sacral spinal cord. This system is sometimes referred to as the craniosacral system because of the location of these cell bodies. Specifically, neurons from particular nuclei in the brainstem or from the lateral horn of the sacral spinal cord (preganglionic neurons) project to terminal ganglia located close to or within the wall of target organs. These fibers release Acetylcholine (ACh) onto nicotinic receptors to excite the ganglionic neurons, which then contact the target tissues within the organ to release ACh, which binds to muscarinic receptors to induce rest-and-digest responses.