Matching Pairs Skeletal SystemOnline version Match the following by Ms. Burton 1 The skull 2 The hardness of bones is called ____________ 3 The ribs 4 Bones are made out of ? 5 The spine Protect the heart, lungs, and other organs in the chest cavity. Crystals of Calcium Protects the brain and forms the shape of the face. Different kinds of tissues/ Made up of vertebrate that support and protect the spinal cord.