Which structure connects the left and right hemispheres?

Which structure connects the left and right hemispheres?

• A. Corpus callosum
• B. Internal capsule
• C. Fornix
• D. Cingulate gyrus

Answer: (A)

Interhemispheric communication relies on a central bridge of crossing fibers that links corresponding areas across the two sides of the brain. The corpus callosum is this largest connecting pathway, spanning the midline to connect the left and right hemispheres and coordinate activity between them. Other options do not serve as a cross-hemisphere connector: the internal capsule carries fibers between the cortex and brainstem or spinal cord; the fornix connects the hippocampus with limbic structures; and the cingulate gyrus is a medial cortical region involved in emotion and attention, not a bridge between hemispheres.

Interhemispheric communication relies on a central bridge of crossing fibers that links corresponding areas across the two sides of the brain. The corpus callosum is this largest connecting pathway, spanning the midline to connect the left and right hemispheres and coordinate activity between them. Other options do not serve as a cross-hemisphere connector: the internal capsule carries fibers between the cortex and brainstem or spinal cord; the fornix connects the hippocampus with limbic structures; and the cingulate gyrus is a medial cortical region involved in emotion and attention, not a bridge between hemispheres.