autonomic nervous system

Component of the nervous system that represents motor innervation of smooth muscle, cardiac muscle & glands. It consists of 2 anatomically distinct, mutually antagonistic components: 1) sympathetic nervous system 2) parasympathetic nervous system In both systems, the pathway of innervation consists of a synaptic sequence of 2 motor neurons. One lies in the brainstem or spinal cord (presynaptic or preganglionic neuron); the other (postsynaptic or postganglionic neuron) lies in one of the autonomic ganglia outside of the central nervous system. Preganglionic fibers of (B-fibers) are thin, but myelinated. Postsynaptic fibers are unmyelinated. The neurotransmitter of the ganglionic synapses is acetylcholine.

Specific

parasympathetic nervous system sympathetic nervous system vagal (nerve) trunk

References

Stedman's Medical Dictionary 27th ed, Williams & Wilkins, Baltimore, 1999

Components

gray rami communicantes white rami communicantes