Projection fibers are primarily composed of which type of connection?

• A. Projection Fibers
• B. Association Fibers
• C. Commissural Fibers
• D. Short Fibers

Answer: (A)

Projection fibers are long-range white matter tracts that connect the cerebral cortex with subcortical targets such as the brainstem, spinal cord, and thalamus. This vertical, distant connectivity is what sets them apart from the other fiber systems. Through structures like the internal capsule and corona radiata, these fibers carry motor commands from cortex to lower centers and sensory information from the body up to the cortex, forming essential pathways such as the corticospinal and thalamocortical tracts. In contrast, association fibers link cortical areas within the same hemisphere, commissural fibers connect corresponding regions across hemispheres, and short fibers connect neighboring gyri within a single hemisphere. So, projection fibers are defined by their long-range connections between the cortex and subcortical regions, making them the best description of their primary role.