Meninges and Cerebrospinal Fluid

The meninges: dura mater, arachnoid mater and pia mater.

1. The meninges are the membranes that envelop the brain and spinal cord of the central nervous system.
2. Dura mater is a thick membrane that is the outermost of the three layers of the meninges that surround the brain and spinal cord.
3. One of three protective membranes covering the brain and spinal cord, the arachnoid mater is interposed between the more superficial and much thicker dura mater and the deeper pia mater.
4. Pia mater is the delicate innermost layer of the membranes surrounding the brain and spinal cord.
5. Cerebrospinal fluid is a clear, colorless body fluid found in the brain and spine. It is produced in the choroid plexuses of the ventricles of the brain.
   

   The cerebrospinal fluid (CSF) circulates in the subarachnoid space around the brain and spinal cord.

6. The ventricular system is a set of four interconnected cavities in the brain, where the cerebrospinal fluid (CSF) is produced.