Since matter at rest tends to stay at rest until acted upon, there must be some mechanism in the brain causing cerebrospinal fluid to move from the choroid plexus to other areas of the central nervous system. Is there some kind of hydraulic pump that causes it to flow from one area to the next?
Also, the ventricular system seems to be more of a continuous cavity, rather than a unidirectional closed circuit. How does the fluid make it's way into the far corners of the lateral ventricles, and other nooks and crannies of the ventricular system without the risk of fluid in some areas staying stagnant?