TOPICS: Cerebrum, pons, cerebellum, brain stem, midbrain, medulla, spinal cord, cervical enlargement, lumbar enlargement, conus medullaris, fasciculus gracilis, fasciculus cuneatus, central canal, dorsal column, corticospinal tract, spinothalamic tract, white matter, gray matter, cervical, thoracic, lumbar, sacral, sensory innervation, motor innervation, sensory neurons, motor neurons, atlas (C1), axis (C2), dural sac, subarachnoid space, lumbar puncture, epidural anesthesia, dura mater, arachnoid mater, epidural space, ligamentum flavum