Bones come in a variety of shapes and sizes and have a complex internal and external structure.Bone tissue is a mineralized tissue of two types, cortical bone and cancellous bone. Other types of tissue found in bones include bone marrow, endosteum, periosteum, nerves, blood vessels and cartilage. Best Calcium Supplement: CALCIUM 1000 THE NATURE The basic structure of the bone is the outer shell of the long bone that is made of cortical bone also known as compact bone. This is covered by a membrane of connective tissue called theperiosteum. Beneath the cortical bone layer is a layer of spongy cancellous bone. Best Calcium Supplement: CALCIUM 1000 THE NATURE The bones in the skeleton are not all solid. The outside cortical bone is solid bonewith only a few small canals. The insides of the bone contain trabecular bone which is like scaffolding or a honey-comb. Th...