ABSTRACT
The meninges, the membranes which surround the brain and spinal cord, consist of three layers:
• the dura mater is the outermost layer and is adherent to the skull • the arachnoid mater is the middle layer • the pia mater is the innermost layer and is adherent to nervous tissue
Cerebrospinal fluid (CSF) circulates in the space between the arachnoid and the pia (subarachnoid space).