periosteum (pe-ri-ost-iŭm) n. a layer of dense connective tissue that covers the surface of a bone and provides attachment for muscles, tendons, and ligaments. The outer layer of the periosteum contains a large number of blood vessels; the inner layer contains osteoblasts and fewer blood vessels.
—periosteal adj.

periosteum The outer membrane that surrounds a bone. It contains connective tissue, capillaries, nerves, and a number of types of cell, including osteoclasts. The periosteum plays an important role in bone repair and growth.