What structure protects the brain and spinal cord?

The correct answer is the meninges, which are a set of three protective membranes that envelop the brain and spinal cord. These layers – the dura mater, arachnoid mater, and pia mater – serve multiple functions, including providing a protective barrier against physical impact, filtering fluids, and maintaining the stability of the central nervous system. The meninges also contain cerebrospinal fluid, which further cushions the brain and spinal cord, allowing for additional protection against injury. This specialized structure is crucial for sustaining the health and functionality of the nervous system components housed within the cranial and vertebral cavities.

Bone provides a primary structural barrier and protection for the brain and the spinal cord, but it is not as directly involved in the overall functioning and cushioning of the central nervous system as the meninges. Cartilage does not provide the same protective role in this context, and the endosteum, while related to bone, does not contribute directly to the protection of the brain and spinal cord. Hence, the meninges are vital for both safeguarding and supporting the central nervous system.