A sickle-shaped fold of dura mater separating the two hemispheres of the cerebrum is called which?

• A. Falx cerebri
• B. Tentorium cerebelli
• C. Falx cerebelli
• D. Dural fold

Answer: (A)

The falx cerebri is a sickle-shaped fold of dura mater that splits the two cerebral hemispheres, darting down into the longitudinal fissure. It anchors anteriorly to the crista galli and posteriorly to the internal occipital crest, creating a stable partition. Its margins form important venous channels—the superior sagittal sinus along the top edge and the inferior sagittal sinus along the free lower edge—helping drain blood from the brain. This specific shape and location distinguish it from other dural folds: the tentorium cerebelli lies horizontally between the cerebrum and cerebellum, the falx cerebelli separates the cerebellar hemispheres, and a dural fold is a general term that doesn’t specify the particular partition described here.