Pachymeninges: The Thick Outer Meningeal Layer Protecting the Brain and Spinal Cord

Definition

The pachymeninx (or pachymeninges) is the thick, tough outer layer of the meninges—the connective tissue membranes enveloping the brain and spinal cord. It is synonymous with the dura mater.

Structure and Location

• Composed of dense fibrous connective tissue.
• Contains blood vessels, nerves, and lymphatic channels.
• Outer periosteal layer adheres to the skull; inner meningeal layer faces the arachnoid mater.
• Continuous with the epineurium of spinal nerves.

Function

Provides robust mechanical protection for the central nervous system, maintains CSF-containing spaces, and contributes to the blood-brain barrier integrity.