Stock Photo - Adult bone structure, bone development, cartilage structure, humerus. This illustration represents the bony structures of the humerus in an adult. At the top, the proximal epiphysis is covered with cartilage. An epiphyseal line (whiter) separates the epiphysis from the metaphysis. Epiphysis and metaphysis are made up of cancellous bone. Then the body of the bone is the diaphysis made up of compact bone. In the center, the medullary canal is largely vascularized. The bony areas of spongy and compact bone are covered by the periosteum (in dark beige). The lower part of the humerus is full, with the disc epiphysis covered with articular cartilage (trochlea). It constitutes the upper part of the elbow joint with the ulna and radius. A horizontal section is shown at the level of the shaft of the humerus. This cut at the bottom of the illustration shows the bone structure with the periosteum on the periphery (dark beige), then the interior is made up of compact bone around the medullary cavity. The medullary cavity is larger in adults than in infants and children.