The intrahemispheric fissure that separates the cerebral hemispheres corresponds to which structure?

• A. Falx cerebri
• B. Tentorium cerebelli
• C. Cerebral aqueduct
• D. Cavum septum pellucidum

Answer: (A)

The key idea is the midline separation between the two cerebral hemispheres. The structure that descends within that fissure to separate them is the falx cerebri, a large dural fold. It runs from the anterior crista galli to the internal occipital protuberance and houses the major venous sinuses along its margins—the superior sagittal sinus along its upper edge and the inferior sagittal sinus along its lower edge. The other options refer to different partitions or spaces: the tentorium cerebelli separates cerebrum from cerebellum, the cerebral aqueduct links the third and fourth ventricles in the midbrain, and the cavum septum pellucidum is a potential space within the septum pellucidum. Therefore, the falx cerebri is the structure associated with the intrahemispheric fissure that separates the cerebral hemispheres.