Illustration of the dural venous sinus tributaries from the cerebral veins. Venous blood from deep within the brain drains into the dural sinuses (blue) through deep and superficial cerebral veins. Located deep to the skull, the dural sinuses are venous channels within the dura mater, a tough layer of connective tissue forming the outer layer of the meninges of the brain. The venous blood drains into the internal jugular vein. From Testut, L. 1930. Traite d'anatomie humaine, vol. 3. Doin and Co, Paris.