Arachnoid membranes

Arachnoid membranes represent sheet-like connective tissue that crosses the subarachnoid space, from the pia mater to the arachnoid mater, dividing the subarachnoid space into cisterns. A number of these membranes are named 1:

• Liliequist membrane: separates the chiasmatic cistern and interpeduncular cistern
• anterior pontine membranes: separate the prepontine cistern (midline) from the cerebellopontine cisterns (laterally)
• lateral pontomesencephalic membranes: separate the ambient cisterns from the cerebellopontine cisterns
• medial pontomedullary membrane: separates the premedullary cistern from the prepontine cisterns
• lateral pontomedullary membranes: separate the cerebellopontine cistern from the cerebellomedullary cisterns