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The sympathetic trunk is a fundamental part of the sympathetic nervous system, and part of the autonomic nervous system. It allows nerve fibres to travel to spinal nerves that are superior and inferior to the one in which they originated. Also, a number of nerves, such as most of the splanchnic nerves, arise directly from the trunks.
Afferent nerve cell bodies bring information from the body to the brain and spinal cord, while efferent nerve cell bodies bring information from the brain and spinal cord to the rest of the body. The cell bodies create long sympathetic chains that are on either side of the spinal cord. They also form para- or pre-vertebral ganglia of gross anatomy.
There are two kinds of neurons involved in the transmission of any signal through the sympathetic system: pre-ganglionic and post-ganglionic. The shorter preganglionic neurons originate in the thoracolumbar division of the spinal cord specifically at T1 to L2~L3, and travel to a ganglion, often one of the paravertebral ganglia, where they synapse with a postganglionic neuron.
The upper two lumbar ganglia (L1 and L2) of the sympathetic chain also give rise to the lumbar splanchnic nerves. Splanchnic nerves are paired visceral nerves carrying preganglionic sympathetic and general visceral afferent fibers. The lumbar splanchnic nerves travel through the lumbar sympathetic ganglion but do not synapse there.
Another major difference between the two ANS (autonomic nervous systems) is divergence. Whereas in the parasympathetic division there is a divergence factor of roughly 1:4, in the sympathetic division there can be a divergence of up to 1:20. This is due to the number of synapses formed by the preganglionic fibers with ganglionic neurons.
Prevertebral ganglia (or collateral ganglia, [1] or preaortic ganglia [2]) are sympathetic ganglia situated along the midline, anterior to the aorta and the vertebral column. . The prevertebral ganglia are the celiac ganglia (including the aorticorenal ganglia), the superior mesenteric ganglion, and the inferior mesenteric gangli
The Secret Service at the venue, however, was more sympathetic, and supposedly convinced the disgruntled cop to let Ava and her boyfriend leave without issue, she alleged.
The sympathetic ganglia here, are found in two chains: the pre-vertebral and pre-aortic chains. The activity of autonomic ganglionic neurons is modulated by "preganglionic neurons" located in the central nervous system. Preganglionic sympathetic neurons are located in the spinal cord, at the thorax and upper lumbar levels.