What is the third layer of the meninges that is closest to the brain and spinal cord called?

The third layer of the meninges closest to the brain and spinal cord is known as the pia mater. This delicate and thin membrane directly envelops the surface of the brain and spinal cord, providing a protective barrier and helping to support the vascular structures that supply blood to the central nervous system. The pia mater is integral to maintaining the health of neural tissue by allowing for nutrient exchange and contributing to the protection and stability of the central nervous system's environment. Its close proximity to the brain and spinal cord enables it to play a significant role in safeguarding these critical structures while also facilitating the exchange of fluids and materials necessary for their function.