I was just wondering if you know what the mechanism is that

Solution

Your brain and spinal cord sit inside your skull and the cavity that runs down inside your spinal column, and they\'re invested in some layers called the meninges which wrap up the brain and spinal cord.  Inside those layers is a fluid called cerebrospinal fluid, and the brain bops around in that fluid. It effectively acts as a cushion to support the tissue because the nerves in the brain are very delicate and they need that additional cushioning support.

The cerebrospinal fluid is actually made right inside the brain. You have a network of blood vessels called the choroid plexus and those blood vessels work rather like a coffee filter. The blood goes through them and the walls are slightly leaky, so liquid, but not cells, comes out of the blood and goes inside some holes in the brain called ventricles. This liquid flows out of those ventricles and then out into the space around the brain.  Right at the top of your head, between the two hemispheres is a structure called the falx cerebri and in there is a very large blood vessel called the sagittal sinus.  The dura, which is one of the layers of the meninges, makes that special blood vessel and it