Emergency Medical Technician (EMT) Intermediate Practice Exam

What are the three meningeal layers of the central nervous system, beginning with the outermost layer?

1. Pia mater, arachnoid, dura mater

2. Arachnoid, pia mater, dura mater

3. Dura mater, arachnoid, pia mater

4. Subarachnoid, arachnoid, dura mater

The correct answer is: Dura mater, arachnoid, pia mater

The correct response identifies the three layers of the meninges, which are protective coverings of the central nervous system. Beginning with the outermost layer, the dura mater is the toughest and most durable of the three meningeal layers, providing a strong protective barrier for the brain and spinal cord. Just beneath the dura mater is the arachnoid mater, a web-like layer that provides a cushion for the brain. This layer is important as it manages the flow of cerebrospinal fluid, which surrounds the brain and spinal cord, helping to protect these structures from injury and providing essential nutrients. The innermost layer, the pia mater, is a delicate and thin membrane that closely adheres to the surface of the brain and spinal cord. This layer plays a crucial role in protecting the central nervous system as well, being involved in the vascular supply that delivers blood to the nervous tissue. Understanding the arrangement of these layers is crucial for grasping how they work together to protect the central nervous system from physical impacts and infections.