Final answer:
Intermediate filaments form the nuclear lamina that lines the inside of the nucleus, providing it with structural support and protection.
Step-by-step explanation:
The cytoskeleton filament system that lines the inside of the nucleus to protect it is known as nuclear lamins, which are a specific type of intermediate filaments. These intermediate filaments are a diverse group of cytoskeletal fibers that provide structural support and maintain the position of the nucleus by forming the nuclear lamina. They are composed of polymerized subunits made up of proteins like lamin, which is found primarily in the lamina structure just inside the nuclear envelope.