What is the main tract that connects the two cerebral hemispheres?

• A. Corpus callosum
• B. Anterior commissure
• C. Fornix
• D. Internal capsule

Answer: (A)

The main idea here is interhemispheric communication through a central midline tract. The corpus callosum is the largest white-matter bridge connecting the two hemispheres, allowing rapid exchange of motor, sensory, and cognitive information between corresponding cortical areas. Its size and breadth make it the primary pathway for linking the left and right sides of the brain, with different parts connecting various regions (for example, the genu links frontal areas and the splenium connects occipital regions).

The anterior commissure also carries interhemispheric fibers, but it’s smaller and mainly connects parts of the temporal lobes and olfactory regions, not the major cross-hemispheric communicator. The fornix is part of the limbic system, routing information from the hippocampus to other limbic structures, not serving as a broad interhemispheric conduit. The internal capsule houses projection fibers between the cortex and subcortical structures, and it does not primarily link the two hemispheres across the midline.