pain pathway

n. Any of numerous nerve paths that carry the sensations of pain from nerve endings toward the central nervous system or efferent pathways that inhibit pain. Afferent pain fibers include myelinated fibers, which rapidly conduct pain information, and unmyelinated fibers, which are slow in conductance, which 
together form the ascending tracts connecting with the anterolateral system, the central gray matter, the reticular formation, the thalamus and hypothalamus, and the cingulate gyrus.