The meninges are three protective membranes that surround the brain and spinal cord. These layers are called the dura mater, arachnoid mater, and pia mater. They help protect the central nervous system from injury and infection, as well as provide a supportive structure. The outermost layer, the dura mater, is tough and durable, while the middle layer, the arachnoid mater, is web-like and contains cerebrospinal fluid. The innermost layer, the pia mater, is thin and closely adheres to the surface of the brain and spinal cord. Together, the meninges play a crucial role in maintaining the health and function of the central nervous system.