Nerve
Sympathetic trunk
Linked ganglia extending along both sides of the spine
High-yield
White rami bring preganglionic fibers from the thoracolumbar outflow, conventionally T1–L2. Gray rami distribute postganglionic fibers to spinal nerves throughout the body.
Overview
Each sympathetic trunk provides a route for fibers to travel above or below their spinal entry level. The paired chains extend from the upper neck toward the coccyx, where they meet at the ganglion impar.
Reference facts
- Origin
- Preganglionic cell bodies in the thoracolumbar spinal cord's lateral gray matter
- Root value
- White rami principally T1–L2, sometimes extending to L3; gray rami connect at all spinal levels
- Course
- Bilateral paravertebral chains from neck to coccyx, with variable ganglion number and a terminal ganglion impar
- Motor
- Distributes sympathetic output to vessels, sweat glands, arrector pili and visceral organs, using chain or prevertebral relays
- Sensory
- Visceral afferents may pass through the trunk en route to spinal sensory ganglia and the spinal cord
Clinical correlation
Visceral afferents can travel alongside sympathetic pathways and converge centrally with somatic signals. This contributes to referred pain, whose location alone cannot establish the underlying cause.
Frequently asked questions
What are the roots of the sympathetic trunk?
White rami principally T1–L2, sometimes extending to L3; gray rami connect at all spinal levels.
What muscles does the sympathetic trunk supply?
Distributes sympathetic output to vessels, sweat glands, arrector pili and visceral organs, using chain or prevertebral relays.
What is the sensory distribution of the sympathetic trunk?
The sympathetic trunk carries sensation from the visceral afferents may pass through the trunk en route to spinal sensory ganglia and the spinal cord.
What is the course of the sympathetic trunk?
Bilateral paravertebral chains from neck to coccyx, with variable ganglion number and a terminal ganglion impar.