Nerve · Thoracic spine

Dorsal nerve roots

Radices dorsales

The sensory half of every spinal nerve, before the two halves join. A dorsal root is a fan of fine rootlets leaving the back of the spinal cord that gathers into a single bundle and runs out toward the gap between the vertebrae, carrying traffic in one direction only: inwards, from skin, muscle, joint and gut to the cord. Every dorsal root bears a visible swelling near its end — the dorsal root ganglion — which is where the sensory nerve cells themselves live. Because the roots stay strictly separated by direction until they meet, this is the one place in the nervous system where sensation and movement can be interrupted independently of each other.