11. This is due to the number of synapses formed by the preganglionic fibers with ganglionic neurons. 12. The enhanced ciliospinal reflex in asymptomatic patients with cluster headache is due to preganglionic sympathetic mechanisms. 13. Preganglionic sympathetic neurons are located in the spinal cord, at the thorax and upper lumbar levels.14. The test is the following : First stimulate the preganglionic fiber and notice the response that appears. 15. The sacral sympathetic nerves contain a mix of preganglionic and postganglionic sympathetic fibers, but mostly postganglionic. 16. The activity of autonomic ganglionic neurons is modulated by preganglionic neurons located in the central nervous system. 17. The first synapse ( preganglionic neuron to postganglionic neuron ) is mediated by nicotinic receptors activated by acetylcholine. 18. The remaining preganglionic fibers continue as the mixed facial nerve proper as it extends through the facial canal. 19. The greater petrosal nerve, which carries preganglionic parasympathetic fibers, emerges from the anterior aspect of the ganglion. 20. Because it is innervated by preganglionic nerve fibers, the adrenal medulla can be considered as a specialized sympathetic ganglion.
