The Pia Mater is one of the three protective membranes, known as meninges, that surround the brain and spinal cord. It is the innermost layer, lying directly against the surface of the brain and spinal cord. The Pia Mater is thin and delicate, containing blood vessels that supply nutrients to the nervous tissue. This membrane plays a crucial role in protecting the central nervous system. It helps to maintain the shape of the brain and spinal cord while also providing a barrier against infections. The other two layers of the meninges are the Arachnoid Mater and the Dura Mater, which provide additional protection and support.