Anatomical Section of the Spinal Cord and Its Nerve Roots

Description

Centered in the section, the butterfly-shaped substantia grisea forms slender posterior (dorsal) horns and broader anterior (ventral) horns, with a lateral horn implied where thoracic or upper lumbar levels are taught. A pinpoint canalis centralis lies at the gray commissure, surrounded by substantia alba arranged into posterior, lateral, and anterior funiculi (columns) that carry ascending and descending tracts. Fine dorsal rootlets emerge from the posterolateral sulcus and converge into the radix posterior, while ventral rootlets exit anterolaterally as the radix anterior; the paired roots unite laterally to form a mixed spinal nerve just beyond the cord. Cross-sections like this anchor spinal neuroanatomy because they link function to position: dorsal horn sensory processing, ventral horn lower motor neurons, and white-matter columns tied to long-tract syndromes. It is the clearest way to teach why an anterior cord infarct preferentially damages corticospinal and spinothalamic pathways while sparing dorsal column modalities, and why a ventral root lesion produces flaccid weakness without primary loss of sensation. Rootlet organization before the main spinal nerve is the key landmark for distinguishing radiculopathy from plexopathy and for explaining segmental patterns. Use this plate in gross anatomy and neuroanatomy courses when introducing spinal cord levels, gray-versus-white matter organization, and dorsal versus ventral root function, and in clinical teaching files for Brown-Sequard syndrome, anterior spinal artery syndrome, and compressive radiculopathy from disc herniation. It also fits neurosurgery and anesthesia materials covering laminectomy orientation and epidural or intrathecal procedures where nerve roots and their trajectories matter. Anatomical accuracy verified by SciePro's Medical Advisory Board.