What is spinal cord and how it is protected in the human body

The spinal cord is a soft bundle of nerves that extends from the base of the brain to the lower back. It runs through the spinal canal and is protected by the bones of the spine (vertebrae). Messages between the brain and the nerve roots travel up and down the spinal cord, making it possible for the brain and body to communicate. The discs cushion the vertebrae and provide flexibility to the spine and spinal cord.

The answer is Crust and uppermost mantle