Which is the outermost layer of the meninges?

Which is the outermost layer of the meninges?

• A. Arachnoid mater
• B. Pia mater
• C. Subarachnoid space
• D. Dura mater

Answer: (D)

Meninges are three protective layers around the brain and spinal cord, with the outermost being the dura mater. This tough, fibrous membrane forms a sturdy protective sheath and, in the cranial cavity, lines the inside of the skull while also contributing to folds that partition brain regions. Beneath it is the arachnoid mater, a delicate sheet, and beneath that lies the pia mater, which clings directly to the brain’s surface. The space between the arachnoid and pia is the subarachnoid space, filled with cerebrospinal fluid. Since the arachnoid is the middle layer and the pia is the innermost, the dura mater is the outermost layer.

Meninges are three protective layers around the brain and spinal cord, with the outermost being the dura mater. This tough, fibrous membrane forms a sturdy protective sheath and, in the cranial cavity, lines the inside of the skull while also contributing to folds that partition brain regions. Beneath it is the arachnoid mater, a delicate sheet, and beneath that lies the pia mater, which clings directly to the brain’s surface. The space between the arachnoid and pia is the subarachnoid space, filled with cerebrospinal fluid. Since the arachnoid is the middle layer and the pia is the innermost, the dura mater is the outermost layer.