What are the white matter tracts called?

• A. Dorsal root
• B. Dorsal root ganglion
• C. Funiculi
• D. Ventral root

Answer: (C)

White matter tracts in the spinal cord are bundles of myelinated axons that carry signals up and down the nervous system. These bundles are called funiculi, forming the posterior (dorsal), lateral, and anterior (ventral) white matter columns that house major ascending and descending pathways. The other terms—dorsal root, dorsal root ganglion, and ventral root—refer to nerve roots and a sensory ganglion associated with the peripheral nervous system, not to the white matter tracts inside the spinal cord. So the white matter tracts are called funiculi.