Histology Course A III 11d Department of Pathology, University of Zurich histologycourse

A III 11d developing long bone (normal finding) HE  
   A section through the diaphysis and epiphysis of a long bone is shown. The compacta is broad and multiple well formed interconnecting trabeculae are present. Some trabeculae still exhibit remnants of calcified cartilage. The epiphyseal cartilage displays zonation; reserve cartilage, zones of cartilage proliferation, hypertrophy, calcification and resorption can be distinguished. Bone deposition occurs on the calcified cartilage spicules at the resorption zone (enchondral ossification). A second ossification centre within the epiphysis has not been generated yet.
Bone spiculae are formed by enchondral ossification, whereas the compacta is formed by intramembranous ossification.