Meninges, Ventricular System and Vascular System

The central nervous system(CNS) is enwrapped by protective coverings, the meninges. In addition in the center of the CNS is a fluid-filled space (the ventricular system) that shock mounts the CNS. The cerebrospinal fluid (CSF) is formed in the ventricular system and fills the ventricular space and meninges. The CSF also forms the extracellular fluid within the CNS. The CNS is also provided with a remarkable blood supply. Finally, the CNS is surrounded by the bony vertebrae and skull, which can be reviewed in one of the many excellent gross anatomy texts.

The brain is enclosed by three membranes: the dura mater, arachnoid, and pia mater. These protective fluid-filled membranes are formed by connective tissue with embedded nerves, especially in the dura. The dura mater is the most external membrane, followed by the arachnoid, and, finally, the pia mater, which adheres to the central nervous system (CNS).