North Carolina EMT State Practice Exam

What protective covering over the brain is referred to as the dura?

1. A soft membrane surrounding the brain

2. A leathery covering next to the skull

3. A fluid-filled sac

4. A thin layer of cells

The correct answer is: A leathery covering next to the skull

The dura mater is the outermost layer of the meninges, which are the protective coverings of the brain and spinal cord. It is known for its tough and leathery consistency, providing a strong barrier that helps protect the delicate structures of the brain. Its position directly beneath the skull further emphasizes its role in safeguarding the brain from injury. The dura mater is responsible for providing structural integrity and is also involved in the creation of the intracranial space, which houses cerebrospinal fluid and plays a role in circulation of that fluid. In the context of the other choices, a soft membrane surrounding the brain would describe the pia mater, which is much more delicate and closely adheres to the brain's surface. A fluid-filled sac typically refers to spaces like ventricles in the brain or the surrounding layers filled with cerebrospinal fluid but doesn't accurately describe any of the meningeal layers. A thin layer of cells might suggest the arachnoid mater, which is also a protective layer but does not convey the toughness and positioning of the dura mater. Thus, B accurately captures the nature and function of the dura as a tough, leathery covering next to the skull.