 3 layers: The Dura Mater The Arachnoid The Pia Mater Specialized membranes that provide: physical stability and shock absorption to the brain structural support to large blood vessels that supply the CNS

Double-layered external covering  Top layer attaches to the inner surface of the skull (periosteum)  Meningeal layer—outer covering of the brain Folds inward in several areas (dural folds)

Separated from the dura mater by the subdural space. web-like The web houses pockets of cerebrospinal fluid  Shock absorber and transporter

Internal innermost layer Clings to the surface of the brain Main function is circulation  Highly vascular

CSF: clear, colorless fluid that circulates around the brain and spinal cord. Functions  protects the brain from damage against the skull  provides a “bath” for the brain to float in, decreasing its effective weight.

 White matter Is superficial Contains myelinated and unmyelinated axons  Gray matter Surrounds central canal of spinal cord Contains neuron cell bodies, neuroglia, unmyelinated axons Has projections (gray horns)