Problem:

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.

Question: Do both these lead the same place?

Question: 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?

Give reasoning with your answer.