What is the large band of neural fibers connecting the two brain hemispheres and carrying messages between them?

• A. Corpus callosum
• B. Fornix
• C. Thalamus
• D. Hippocampus

Answer: (A)

The key structure is a thick bundle of axons that acts as the main bridge between the two brain halves. This large band, known as the corpus callosum, carries neural messages back and forth, allowing the left and right hemispheres to communicate and work together on complex tasks like movement, sensation, and thinking. It’s the primary commissural tract that connects corresponding areas across sides, so information can be integrated across the brain.

The other options have different roles. The fornix is a pathway within the limbic system linking memory-related areas, the thalamus serves as a central relay station for many sensory and motor signals, and the hippocampus is crucial for forming memories. None of these form the large cross-hemisphere bridge that enables interhemispheric communication like the corpus callosum.