MICROANATOMY

Detailed explanation-1: -The outer walls of the diaphysis (cortex, cortical bone) are composed of dense and hard compact bone, a form of osseous tissue.

Detailed explanation-2: -Most of the diaphysis is formed by compact cortical bone, whereas the inside of the metaphysis and the epiphysis, as well as of short tubular and flat bones contains trabecular (cancellous) bone tissue.

Detailed explanation-3: -The walls of the diaphysis are compact bone. The epiphyses, which are wider sections at each end of a long bone, are filled with spongy bone and red marrow. The epiphyseal plate, a layer of hyaline cartilage, is replaced by osseous tissue as the organ grows in length.

Detailed explanation-4: -Compact bone consists of closely packed osteons or haversian systems. The osteon consists of a central canal called the osteonic (haversian) canal, which is surrounded by concentric rings (lamellae) of matrix. Between the rings of matrix, the bone cells (osteocytes) are located in spaces called lacunae.