What is the potential space between the skull and dura mater that can fill with blood after trauma?

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

Answer: (B)

The space between the skull and the dura mater is the epidural space. It’s a potential space that isn’t a true cavity under normal conditions, but trauma can create or reveal it as blood accumulates in that area. The most common source is an injury to the middle meningeal artery, and the resulting epidural hematoma fills this space, often expanding rapidly and pressing on brain tissue. This is different from a subdural hematoma, which involves the space between the dura and arachnoid due to torn bridging veins. The dura mater and arachnoid mater are membranes themselves, not spaces that typically fill in this way.