ch 12

inner, delicate tissue rich with tiny blood vessels; clings tightly to the surface of the brain, following every condition

middle layer that forms a loose covering that never dips into the cerebral sulci

• Forms a liquid cushion in and around the brain and spinal cord, giving buoyancy to the CNS
• Reduces weight of brain by 97%, preventing pressure under its own weight
• protects the CNS from blows and other trauma helps nourish the brain