Human skull. Historical artwork of a human skull. The skull is the bony skeleton of the head. It consists of the cranium, which encloses and protects the brain, and facial bones, which contain cavities for the eyes (orbits) and nose. The mandible (lower jaw) articulates with the skull. With the exception of the mandible, all of the skull bones are connected by immovable joints called sutures (seen especially on the cranium). This artwork is by Jan van Riemsdyck and was published in 1755.