The pia mater is the innermost layer of the meninges and is the vascularized meninx.
Anatomy
The pia mater is directly adjacent to the brain parenchyma and forms the mesodermal side of the pial-glial boundary[^1]. Vessels branch off from the pia mater into the brain parenchyma and are accompanied by it for some distance into the depth (pial funnels).
