Which layer forms the outermost protective covering of the brain when the meninges are considered as a whole?

Which layer forms the outermost protective covering of the brain when the meninges are considered as a whole?

• A. Pia mater
• B. Arachnoid mater
• C. Grey Matter
• D. Dura mater

Answer: (D)

Dura mater is the outermost protective covering. It’s a tough, fibrous membrane that sits just inside the skull and forms an outer periosteal layer plus an inner meningeal layer; together they envelope the brain and can separate to create dural partitions, but the entire meninges sheath is topped by this tough layer. Beneath it are the arachnoid mater (middle, web-like) and the pia mater (innermost, closely hugging the brain). Grey matter is brain tissue, not a protective covering, so it isn’t part of the outer envelope.

Dura mater is the outermost protective covering. It’s a tough, fibrous membrane that sits just inside the skull and forms an outer periosteal layer plus an inner meningeal layer; together they envelope the brain and can separate to create dural partitions, but the entire meninges sheath is topped by this tough layer. Beneath it are the arachnoid mater (middle, web-like) and the pia mater (innermost, closely hugging the brain). Grey matter is brain tissue, not a protective covering, so it isn’t part of the outer envelope.