Bone chemical components ; Periosteum - This thin membrane on the outside of the bone is made up of nerves and arteries. It contains nerves and veins. Compact sister-- this is the outer part of the bone , which can be seen. Cancelous sister - it looks like a sponge, not as hard as a compact bone. It covers the marrow inside the bone. Bone growth Regular bone loss and the formation of new bones is called bone metabolism. Osteoblasts are two important cells involved in this process - these cells form new bones. Osteoclasts - These cells are responsible for the regular loss of bone. By the combination of these two cells, the body gets its essential minerals. This work continues throughout life.