Ventral ramus (anterior ramus)The larger branch of a spinal nerve, to the front and sides. In the chest each one runs between two ribs as an intercostal nerve.
Dorsal ramus (posterior ramus)The smaller branch, which turns back. It supplies the back's deep muscles and skin.
Lateral cutaneous branchA branch that leaves about midway round the chest. It divides into a front and a back twig for the skin.
Anterior cutaneous branchThe end of the nerve, beside the breastbone. It turns forward to the skin on the chest's front.
At the spine 8
Dorsal root (posterior root)The root that brings sensory fibers into the cord.
Dorsal root ganglion (spinal ganglion)A swelling on the dorsal root. It holds the cell bodies of the sensory neurons.
Ventral root (anterior root)The root that carries motor fibers out of the cord.
Spinal nerveThe short trunk where the two roots join. It carries both sensory and motor fibers.
Meningeal branchA small branch that turns back into the vertebral canal. It supplies the vertebrae, their ligaments and the coverings of the cord.
White ramus communicansThe link that carries fibers from the nerve to the sympathetic trunk. Only the thoracic and upper lumbar nerves have one.
Gray ramus communicansThe link that returns fibers from the sympathetic trunk to the nerve. Every spinal nerve has one.
Sympathetic trunk ganglionA ganglion of the sympathetic trunk, beside the vertebral column.
How this list was compiled: Every name checked on 2026-10-01 in at least two of these. (1) Henry Gray, Anatomy of the Human Body (1918), The Spinal Nerves, The Posterior Divisions and The Thoracic Nerves, https://www.bartleby.com/lit-hub/anatomy-of-the-human-body/6-the-spinal-nerves/ and https://www.bartleby.com/lit-hub/anatomy-of-the-human-body/6c-the-thoracic-nerves/. (2) Wikipedia, English edition, Spinal nerve, Dorsal ramus of spinal nerve, Ventral ramus of spinal nerve, Ramus communicans, White ramus communicans, Gray ramus communicans, Meningeal branches of spinal nerve and Sympathetic trunk, https://en.wikipedia.org/wiki/Spinal_nerve. (3) Kenhub, Spinal nerves and Intercostal nerves, https://www.kenhub.com/en/library/anatomy/spinal-nerves and https://www.kenhub.com/en/library/anatomy/intercostal-nerves. Wikipedia’s article on the intercostal nerves repeats the 1918 text, so it is not counted for the two cutaneous branches; they rest on the other two. Detail lines are in our own words. Licence: own work
The drawing: Drawn for this site on 2026-10-01 from plain geometry; nothing traced. Licence: own work
How it works
The first drawing is the chest cut across, back at the top, with one spinal nerve followed from the spine to the breastbone. The second is the same nerve close up, where its roots join and its branches begin.
Read the full guide
Round the chest first, then in close
Number 1 is the ventral ramus, the long branch that runs round inside the chest wall. Number 2, the dorsal ramus, turns back to the muscles and skin of the back. Numbers 3 and 4 are the skin branches: the lateral cutaneous branch at the side and the anterior cutaneous branch beside the breastbone. In close, 5 to 7 are the dorsal root, its ganglion and the ventral root, and 8 is the short spinal nerve they form. Number 9 is the thin meningeal branch. Numbers 10 and 11 are the white and gray rami communicantes, and 12 is the sympathetic trunk ganglion they join.
Roots come before the spinal nerve and rami after it. There is a dorsal and a ventral one of each.
The arrowheads tell the two links apart: white carries fibers to the ganglion, gray brings them back.
Questions and answers
What are the branches of a spinal nerve?
A dorsal ramus to the back, a larger ventral ramus to the front and sides, a small meningeal branch that turns back into the vertebral canal, and the rami communicantes, which link the nerve to the sympathetic trunk.
What is the difference between a root and a ramus?
Roots join the cord to the nerve: the dorsal root carries sensory fibers in and the ventral root carries motor fibers out. Rami are the branches after the two have joined, so each ramus carries both kinds.
Where do the cutaneous branches go?
To the skin. In the chest the lateral cutaneous branch leaves about midway round and divides into a front and a back twig. The anterior cutaneous branch is the end of the nerve, beside the breastbone.
Is this the art labeling activity on the distribution of spinal nerve branches?
No. That is the title of a publisher’s homework activity. These drawings are our own and show the same roots, rami and branches, so you can practice the names here. We have no answer key for any activity.