Biology 30 Diploma Practice Test

The meninges are indeed the membranes that envelop the brain and spinal cord, providing a protective layer for these critical components of the central nervous system. There are three layers of meninges—dura mater, arachnoid mater, and pia mater—that each serve not only to safeguard the brain and spinal cord from physical damage but also to help contain cerebrospinal fluid, which cushions these structures. This protective system is essential for maintaining the overall health and function of the nervous system and plays a role in regulating the flow of nutrients and waste products.

In contrast, the other options refer to different aspects of the nervous system. The choice describing fluid that nourishes neurons refers to cerebrospinal fluid but does not capture the broader protective function of the meninges. The option about nerves transmitting impulses pertains to the nervous system's communication pathways rather than its protective structures. Lastly, the reference to cells that protect axons highlights the role of myelin and glial cells, which are not directly related to the meninges. Understanding these distinctions helps clarify the specific function of the meninges within the nervous system.