spinothalamic tract

:  any of four tracts of nerve fibers of the spinal cord that are arranged in pairs with one member of a pair on each side and that ascend to the thalamus by way of the brain stem:a:  one on each side of the anterior median fissure that carries nerve impulses relating to the sense of touch—called also anterior spinothalamic tract, ventral spinothalamic tractb:  one on each lateral part of the spinal cord that carries nerve impulses relating to the senses of touch, pain, and temperature—called also lateral spinothalamic tract