part of part of brain pia mater brain meninx brain pia mater brain pia mater of neuraxis EMAPA:32667 UBERON:0003549 pia mater of neuraxis of brain VHOG:0000470 NCIT:C49335 The fibrous membrane forming the innermost of the three coverings that surrounds the brain within the cranial cavity that is firmly attached to the glial capsule. MA:0000816 pia mater of brain