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The superior cerebellar veins pass partly forward and medialward, across the superior cerebellar vermis. They end in the straight sinus, [1] and the internal cerebral veins, partly lateralward to the transverse and superior petrosal sinuses. The inferior cerebellar veins are larger.
The venous drainage of the cerebrum can be separated into two subdivisions: superficial and deep. The superficial system. The superficial system is composed of dural venous sinuses, sinuses (channels) within the dura mater. The dural sinuses are therefore located on the surface of the cerebrum.
These sinuses play a crucial role in cerebral venous drainage. A dural venous sinus, in human anatomy, is any of the channels of a branching complex sinus network that lies between layers of the dura mater, the outermost covering of the brain, and functions to collect oxygen-depleted blood. Unlike veins, these sinuses possess no muscular coat.
The pathophysiology of cranial venous outflow obstruction involves the disruption of normal venous drainage from the brain. Cerebral veins play a crucial role in draining brain interstitial fluid (ISF), and their significance has been linked in various neurological conditions. [1] It can be caused by extrinsic or intrinsic anomalies. [7]
Also visible in the posterior cranial fossa are depressions caused by the venous sinuses returning blood from the brain to the venous circulation: Right and left transverse sinuses which meet at the confluence of sinuses (marked by the internal occipital protuberance).
CSF returns to the vascular system by entering the dural venous sinuses via arachnoid granulations. [2] These are outpouchings of the arachnoid mater into the venous sinuses around the brain, with valves to ensure one-way drainage. [2] This occurs because of a pressure difference between the arachnoid mater and venous sinuses. [3]
The falx cerebri is a strong, crescent-shaped sheet of dura mater lying in the sagittal plane between the two cerebral hemispheres. [3] It is one of four dural partitions of the brain along with the falx cerebelli, tentorium cerebelli, and diaphragma sellae; it is formed through invagination of the dura mater into the longitudinal fissure between the cerebral hemispheres.
According to this theory, dural holes and intracranial hypotension are symptoms caused by low venous pressure in the epidural space. When leg muscles pump blood towards the heart, and pressure in the inferior vena cava vein becomes negative, the network of epidural veins is overdrained, causing CSF to be aspirated into the epidural space.