Which space lies between the dura mater and arachnoid mater and is seen when filled with blood after trauma?

Which space lies between the dura mater and arachnoid mater and is seen when filled with blood after trauma?

• A. Subarachnoid space
• B. Subdural space
• C. Epidural space
• D. Arachnoid mater

Answer: (B)

The space between the dura mater and the arachnoid mater is the subdural space. It’s a potential gap that normally isn’t filled with fluid, but after head trauma tearing bridging veins can cause blood to accumulate there, producing a subdural hematoma. This differs from the subarachnoid space, which lies between the arachnoid and pia and contains cerebrospinal fluid and vessels, and from the epidural space, which is outside the dura. The arachnoid mater itself is the membrane, not a space.

The space between the dura mater and the arachnoid mater is the subdural space. It’s a potential gap that normally isn’t filled with fluid, but after head trauma tearing bridging veins can cause blood to accumulate there, producing a subdural hematoma. This differs from the subarachnoid space, which lies between the arachnoid and pia and contains cerebrospinal fluid and vessels, and from the epidural space, which is outside the dura. The arachnoid mater itself is the membrane, not a space.