What does the pia mater cover?

The pia mater is the innermost layer of the meninges, which are the protective coverings of the central nervous system, including both the brain and spinal cord. This delicate membrane closely envelops the surface of the brain and spinal cord, following their contours and filling in any crevices or sulci. The pia mater not only provides a protective layer but also contains blood vessels that supply oxygen and nutrients to the underlying neural tissue.

Covering both the brain and spinal cord allows the pia mater to play a crucial role in protecting and supporting the entire central nervous system, ensuring that it remains healthy and functional. This comprehensive coverage, including all crevices, is essential for maintaining the integrity of the nervous system as it allows for efficient communication and nourishment throughout its structure.

Other options do not accurately represent the function or extent of the pia mater, as they either limit its coverage to only one part of the nervous system or inaccurately describe its relationship with the structure of the brain.