What structure protects the brain and is made up of bone?

The cranium is the structure that specifically protects the brain and is composed of bone. It forms the upper part of the skull and provides a sturdy and protective encasement for the brain, safeguarding it from injury and external forces. The cranium consists of several bones that are fused together, creating a rigid structure that not only encases the brain but also supports facial bones, serving as a base for the skull.

In contrast, the vertebrae are part of the spinal column, which protects the spinal cord rather than the brain. The mandible and maxilla are facial bones involved in the structure of the mouth and jaw but do not provide protection to the brain. Since the question focuses specifically on the protective bony structure surrounding the brain, the cranium is the definitive answer.