What is on the outside of the spinal cord?

The outside of the spinal cord is protected by three layers of membranes called meninges: the dura mater (outermost), arachnoid mater (middle), and pia mater (innermost). Between the arachnoid and pia mater is the subarachnoid space, which contains cerebrospinal fluid that cushions the spinal cord. Additionally, the spinal cord is encased within the vertebral column, comprised of individual vertebrae that provide structural support and protection.