B. Meninges Maintain the shape and position of the brain during head and body movements. Dura mater - outermost meningeal layer. Arachnoid mater - beneath and continuous with the dura mater.
Spinal meninges Provide protection to the spinal cord.
Similar to those of the brain except pia mater - much thicker and tougher than the cerebral pia mater. Composition of CSF is in steady state with brain extracellular fluid CSF is absorbed into the venous system via arachnoid villi Cerebral veins drain into large vascular channels called sinuses that are formed by folds in the dura. From the sinuses the venous blood returns to the heart via the jugular vein. The arachnoid villi bring CSF into close approximation with venous blood. CSF is able to flow into the venous system through one way valves as a consequence of bulk flow or pressure gradient differences.