Nerve Roots in the Spinal Cord Section

Description

Seen in transverse section, the spinal cord centers a butterfly-shaped gray matter core with paired dorsal (posterior) horns and ventral (anterior) horns, surrounded by white matter columns (funiculi) arranged into dorsal, lateral, and anterior regions. Fine ventral rootlets emerge from the anterolateral sulcus and converge into a ventral root, while dorsal rootlets enter along the posterolateral sulcus to form the dorsal root. Laterally, dorsal and ventral roots join as a short mixed spinal nerve before continuing into the peripheral nervous system. Clean anatomy. This arrangement matters because it maps directly onto neurologic localization: ventral horn and ventral root lesions produce lower motor neuron weakness with atrophy and hyporeflexia, while dorsal root involvement drives dermatomal sensory loss and radicular pain. Neurosurgeons and anesthesiologists also rely on the dorsal versus ventral separation when discussing selective dorsal rhizotomy for spasticity and when interpreting root-level compression from a posterolateral disc herniation, which typically irritates the exiting or traversing root depending on level and anatomy. The cross-section clarifies why dorsal roots carry afferent fibers and ventral roots carry efferent fibers at the same segment. Use this plate in neuroanatomy and physiology teaching to anchor spinal cord organization, in clinical neurology texts explaining radiculopathy versus myelopathy, and in patient-facing materials that need a clear depiction of dorsal and ventral root contributions to a mixed spinal nerve. Anatomical accuracy verified by SciePro's Medical Advisory Board.