Which structure forms the largest dural fold at the midline separating the two cerebral hemispheres?

• A. Falx Cerebri
• B. Tentorium Cerebelli
• C. Choroid Plexus Structures
• D. Foramen of Monro

Answer: (A)

The falx cerebri is the largest dural fold sitting along the midline to separate the two cerebral hemispheres. It runs in the longitudinal fissure, attaching anteriorly to the crista galli of the ethmoid bone and posteriorly to the internal occipital crest. It houses the superior and inferior sagittal sinuses, helping to stabilize and compartmentalize the brain. The tentorium cerebelli is a different fold that sits between the cerebrum and cerebellum, not between the hemispheres. Choroid plexus structures are within the ventricles and not dural folds, and the foramen of Monro is an opening in the ventricular system, not a dural structure.