Ganglia are 20,000 to 30,000 afferent and efferent nerve cell bodies that run along on either side of the spinal cord.

[1] The fight-or-flight response is adaptive when there is a real and present danger which can be avoided or diminished through increased sympathetic activity.

Sympathetic activity could be increased heart rate, dilated pupils, or sweaty palms, for example.

When the intensity or duration of the response is excessive, the individual may meet criteria for a variety of psychological disorders.

The general rule of interaction of the nerve fibers in the sympathetic nervous system begins at the spinal cord.

It is this ability to move superiorly and inferiorly along the chain that results in the mass response to the sympathetic nervous system.