Central nervous system disorders

III./1.4.: Pia mater

This innermost layer of the meninges is also called the vasculare membrane because of attached vessels of the scull base. The pia mater covers the surface of the brain (also the brain stem and the cerebellum), it goes deep in between the cerebral gyri (sulcus), while at the surface and deep in the sulci the blood vessels penetrate the brain with several small branches.

The pia mater is prolonged to form hornlike sheats for the penetrating vessels. The vessel are trussed in the liquor space by the delicate trabeculae between the arahnoid and the pia mater, thus the vessel are followed by the decreasing compartments of the liquor space. These compartments are called the Virchow-Robin-space. Therefore the vessel and the brain matter are separated by the Virchow-Robin space and the perivascular glial limiting membrane (glia limitans). With the injury or removal of the pia mater the blood supply of the cortex and superficial white matter is consequently ceased.