cerebral venous system
The cerebral venous system, somewhat unlike the majority of the rest of the body, does not even remotely follow the cerebral arterial system.
The cortical veins lie superficially, unlike cortical arteries, and are adherent to the deep surface of the arachnoid mater so that they keep the sulci open . Cortical veins then drain to the nearest dural venous sinus, such as the superior sagittal sinus (which drains the superolateral surface of the hemisphere) and the straight sinus, to the torcula Herophili which lies inferiorly (the confluence of sinuses), then to the transverse sinuses, and sigmoid sinuses and internal jugular veins .
Drainage of the inferior and medial surfaces occur through the straight sinus to the great cerebral vein (of Galen) to the internal cerebral vein and choroid plexus vein, thalamostriate vein and veins of septum pellucidum . The great cerebral vein (of Galen) also gives off two basal veins (of Rosenthal) and with the inferior sagittal sinus, joins the straight sinus .
Cerebral veins have thin walls with no muscular tissue and possess no valves. They emerge from the brain and lie in the subarachnoid space, coursing over the surface of the brain, aggregating into larger channels until they pierce the arachnoid mater and the meningeal layer of the dura mater and drain into the dural venous sinuses.
The whole system may be divided into some sections: