Fig. 12 A. Fasciculus gracilis B. Fasciculus cuneatus Thalamic radiations to lower limb area of postcentral gyrus Thalamic radiations to upper limb area of postcentral gyrus Dorsal columns convey well-localized touch, pressure and vibratory sense from legs (fasciculus gracilis) and arms (fasciculus cuneatus) Third order neuron in ventral postero-lateral nucleus of thalamus Third order neuron in ventral postero-lateral nucleus of thalamus Second order fibers in dorsolateral part of medial lemniscus in pons & midbrain Second order fibers in ventromedial part of medial lemniscus in pons & midbrain Synapse with second order neuron in the cuneate nucleus Second order fibers in dorsal part of medial lemniscus in medulla Synapse with second order neuron in the gracile nucleus Second order fibers in ventral part of medial lemniscus in medulla Internal arcuate fibers are second order fibers that decussate Internal arcuate fibers are second order fibers that decussate First order fiber ascends spinal cord in fasciculus cuneatus First order fiber ascends spinal cord in fasciculus gracilis First order neuron in cervical dorsal root ganglion First order neuron in lumbar dorsal root ganglion Cervical cord Lumbar cord Fig. 12