Nerve
Dorsal root ganglion
Cluster of primary sensory neuron cell bodies on a spinal root
High-yield
Pseudounipolar describes the branching shape of these sensory neurons. The ganglion is not an autonomic relay ganglion; its neurons and supporting glia can nevertheless influence sensory signaling.
Overview
A dorsal root ganglion houses the cell bodies of sensory neurons outside the spinal cord. Each typical neuron has one process that divides into peripheral and central branches, linking a sensory ending with the central nervous system without a relay to another neuron inside the ganglion.
Reference facts
- Origin
- Develops mainly from neural crest cells and forms a swelling along a dorsal spinal root
- Root value
- Usually associated with each paired spinal sensory root; the C1 dorsal root and its ganglion are particularly variable and may be absent
- Course
- Located proximal to dorsal–ventral root union, commonly near or within a foramen; sacral and variant ganglia can lie farther within the canal
- Motor
- Contains primary sensory neuron cell bodies rather than somatic motor neurons or a normal preganglionic-to-postganglionic autonomic relay
- Sensory
- Supports afferent signaling for touch, position sense, pain, temperature and visceral sensation
Clinical correlation
Varicella-zoster virus can remain dormant in sensory ganglia after chickenpox and reactivate as shingles. The painful blistering rash usually follows one or nearby dermatomes on one side, but atypical and disseminated patterns can occur.
Frequently asked questions
What are the roots of the dorsal root ganglion?
Usually associated with each paired spinal sensory root; the C1 dorsal root and its ganglion are particularly variable and may be absent.
What muscles does the dorsal root ganglion supply?
Contains primary sensory neuron cell bodies rather than somatic motor neurons or a normal preganglionic-to-postganglionic autonomic relay.
What is the sensory distribution of the dorsal root ganglion?
The dorsal root ganglion carries sensation from the supports afferent signaling for touch, position sense, pain, temperature and visceral sensation.
What is the course of the dorsal root ganglion?
Located proximal to dorsal–ventral root union, commonly near or within a foramen; sacral and variant ganglia can lie farther within the canal.