The term meninges refers to the three membranous layers that encapsulate the brain (BRN) and the spinal cord (SPC). Listed in order from the brain out, these layers are the pia mater (pia), the arachnoid mater(arac) and the dura mater (dura). They are not part of the brain but a cerebrospinal fluid (CSF)-filled cover that, 1) cushions the brain from a traumatic blow to the head ( Carpenter-1983 ) and. 2) provides the channel for a continuous flow of CSF in and around the BRN and spinal cord (SPC) They are found in the human, macaque, rat and mouse ( NeuroNames ). Updated 13 Dec .