Rate the Effectiveness of the Following Barriers at Preventing Substances

Rate the effectiveness of the following barriers at preventing substances from crossing as either VERY permissive or NOT permissive:
_____ the arachnoid barrier, where CSF drains into the venous return (in the direction of CSF to circulation)
_____ the arachnoid barrier, where CSF drains into the venous return (in the direction of circulation to CSF)
_____ the blood-CSF barrier composed of choroid epithelial cells
_____ the blood-brain barrier composed of endothelial cells
_____ the endothelial cells surrounding vasculature that supplies blood to the circumventricular organs