The meninges comprise the dura mater and the leptomeninges (arachnoid and pia mater).
Dura forms an outer endosteal layer related to the bones of the skull and spine and an inner
layer closely applied to the arachnoid mater. Leptomeninges have multiple functions and
anatomical relationships. The outer parietal layer of arachnoid is impermeable to CSF due to
tight intercellular junctions; elsewhere leptomeningeal cells form demosomes and gap
junctions. Trabeculae of leptomeninges compartmentalize the subarachnoid space and join …