Confusion regarding the ventricle system in the brain I have a hard time finding out a small detail about the ventricle system. As the CSF flows into the 4th ventricle, there's a small foramen in the lateral aspect, as well as an open space bounded by the medulla and cerebellum. Do both these lead the same place? Is the space under the arachnoid matter only accessed through the small foramen, whereas the space between the medulla and cerebellum leads into the spinal column?

I've found the answer. The entire brain and spinal cord is bounded by the arachnoid mater, thus both channels would lead into the subarachnoid space, which also circulates the fluid into the spinal cord region. The CSF exits through the arachnoid granulations, which are like valves, found on the dorsal midline, into the superior sagital sinus, where it returns to the blood stream.