A delta fiber
|A delta fiber|
|File:Medulla spinalis - Substantia grisea - English.svg|
|A delta fiber not labeled, but fibers terminate at Rexed lamina I, labeled at upper left.|
A delta fibers (Aδ) are the fibers which convey fast pain information.
They are much faster than the C fibers because they are myelinated, but they are much thinner than other "A" caliber nerve fibers, so they conduct signals more slowly than the other fibers of that class.
The fibers terminate at Rexed lamina I.