What is the primary function of the pia mater?

The primary function of the pia mater is to tightly adhere to the surface of the brain and spinal cord, providing a protective layer. It is the innermost of the three meninges, which are the protective membranes surrounding the central nervous system. The pia mater is essential for delivering blood vessels to the neural tissue and supporting the overall health of the brain and spinal cord.

While the pia mater does play a role in anchoring the spinal cord to the coccyx, it is actually the filum terminale, a fibrous extension derived from the pia mater, that extends from the conus medullaris and anchors to the coccyx. This connection stabilizes the spinal cord within the vertebral column. The other options provided address different aspects of the meninges or functions that do not specifically relate to the primary role of the pia mater. Thus, the function of providing structural support and being a protective layer is significant in understanding the role this membrane plays in neural health and stability.