Meninges and Spaces of the Brain

Brain Protection

• The brain is protected by 3 membranes, known as meninges, which are:
  • Dura mater
  • Arachnoid membrane
  • Pia mater

Dura Mater

• The outermost layer, strongest and most external
• Continuous with the periosteum of the cranium

Spaces in Meninges

• Epidural space: located between the dura mater and the cranium
• Subdural space: separates the arachnoid membrane from the dura mater
• Sub-arachnoid space: separates the pia mater from the arachnoid mater, contains cerebrospinal fluid (CSF)

Folds of Dura Mater

• Separates and supports structures of the brain, providing cushioning
• Falx cerebri: separates the cerebral hemispheres
• Tentorium cerebelli: forms a partition between the cerebrum and cerebellum
• Supra/infra tentorial: refers to the regions above/below the tentorium cerebelli
• Tentorial notch: an opening that provides communication between the supra and infra tentorial spaces
• Falx cerebelli: separates the two cerebellar hemispheres

Arachnoid Membrane

• Follows the contour of the dura mater

Pia Mater

• Follows the contour of the brain

Learn about the three membranes that protect the brain, including the dura mater, pia mater, and arachnoid membrane, and the different spaces between them.