Dorsal root ganglion (spinal ganglion)A swelling on the dorsal root, full of sensory cell bodies. Nearly every spinal nerve has one on its dorsal root.
CapsuleA coat of dense connective tissue around the ganglion. It runs on into the covering of the nerve.
Bundles of nerve fibersBundles of nerve fibers run the length of the ganglion. They join the dorsal root to the spinal nerve.
Dorsal root (posterior root)The sensory root of a spinal nerve. Its fibers come from the cells of the ganglion and enter the spinal cord.
Ventral root (anterior root)The motor root, which has no ganglion. It passes beside the swelling and joins the dorsal root beyond it.
Spinal nerveThe two roots join here, just beyond the ganglion. The nerve carries both sensory and motor fibers.
The cells 7
Neuron cell body (ganglion cell)The round cell body of a sensory neuron. The cell bodies in a ganglion come in several sizes.
NucleusEach cell body has one large nucleus.
NucleolusA distinct dot inside the nucleus, easy to see on a slide.
Satellite cellsSmall flat glial cells that wrap each cell body. On a slide they show as a ring of small nuclei.
Single process, dividing in a TOne process leaves the cell and divides in a T. One branch runs to the spinal cord and the other out to the body.
Myelinated nerve fibersAxons wrapped in myelin, running among the cells. The large fibers of this ganglion are myelinated.
Connective tissueConnective tissue lies between the cells and around the fibers.
How this list was compiled: Every name checked on 2026-10-03 in at least two of these. (1) Henry Gray, Anatomy of the Human Body, 1918 (public domain), Structure of the Nervous System and The Spinal Nerves, https://www.bartleby.com/lit-hub/anatomy-of-the-human-body/ix-neurology and https://www.bartleby.com/lit-hub/anatomy-of-the-human-body/6-the-spinal-nerves. (2) Histology Guide, by T. Clark Brelje and Robert L. Sorenson of the University of Minnesota, virtual slides MH 050 Dorsal Root Ganglion and MH 059 Sympathetic Ganglia, https://histologyguide.com/slideview/MH-050-dorsal-root-ganglion/06-slide-1.html. (3) Wikipedia, English edition, Dorsal root ganglion, Satellite glial cell and Pseudounipolar neuron, text only. (4) Kenhub, Spinal ganglion, https://www.kenhub.com/en/library/anatomy/dorsal-root-ganglion. (5) Jordan and Ferguson, A Text-book of Histology, 1916 (public domain), Ganglia, https://archive.org/details/textbookofhistol00jord. Hints and detail lines are in our own words. Licence: own work
The drawing: Drawn for this site on 2026-10-03 from plain geometry; nothing traced. A drawing of what a stained section shows, not a photograph. Licence: own work
How it works
The first drawing shows a dorsal root ganglion on its root, cut along its length as a stained section shows it. The second enlarges the cells. Both are drawings, not photographs of a slide.
Read the full guide
Start with the ganglion on its root
Number 1 is the ganglion, the oval swelling on the dorsal root (4). The capsule (2) wraps it, and bundles of nerve fibers (3) run through it. The ventral root (5) passes beside the swelling, and the two roots join as the spinal nerve (6).
Then the cells, enlarged
Each large round cell is the cell body of a sensory neuron (7), with a nucleus (8) and a nucleolus (9). Satellite cells (10) ring every cell body. One cell is drawn with its single process whole (11). Myelinated nerve fibers (12) and connective tissue (13) fill the rest.
Look for the ring of small nuclei around each large cell: those are the satellite cells.
Questions and answers
What cells are in a dorsal root ganglion?
The cell bodies of sensory neurons, each wrapped in small satellite cells, which are glial cells. Nerve fibers and connective tissue lie between them, and a capsule of connective tissue covers the whole ganglion.
Why are dorsal root ganglion neurons called pseudounipolar?
One process leaves the round cell body and then divides in a T. One branch runs to the spinal cord and the other out to the body, and the two work together as a single axon.
How do you tell a dorsal root ganglion from a sympathetic ganglion on a slide?
In a dorsal root ganglion the neurons have a single process and many nerve fibers are large and myelinated. In a sympathetic ganglion the neurons are multipolar and most fibers are thin, with little or no myelin.
Where is the dorsal root ganglion?
On the dorsal root of a spinal nerve, usually in the opening between two vertebrae. The dorsal and ventral roots join just beyond it to form the spinal nerve.