Parasympathetic versus sympathetic
Sympathetic versus parasympathetic
In the sympathetic system, the preganglionic neurons are short, because the ganglia are close to the spinal cord. Postganglionic fibers mostly extend a longer distance to reach their target organ. The sympathetic system shows extensive divergence: a single preganglionic neuron may innervate many postganglionic neurons in different ganglia. The result of this is, that a single sympathetic
neuron can control a variety of visceral organs and thus produce a complex and coordinated response.
Ganglionic neurons of the parasympathetic system are located close to their target organs. A preganglionic neuron innervates one single ganglionic neuron. The effects of parasympathetic stimulation are thus usually brief and restricted to specific organs.