Compact bone is very strong and dense, having no spaces within it other than the Haversian canals.
It is found mainly within the middle of the ends of the bone. These are what fuse after puberty to stop your growth. The marrow cavity is the hollow centre area of the bone which holds bone marrow. The periosteum is the connective tissue which surrounds all bones. The articular cartilage is the substance that protects the ends of the bones and provides a smooth gliding surface, allowing for smooth movement of the joints.