All osteogenic tissue from the neck down is made by endochondral ossification, with the exception of the clavicles. The model that bone will eventually replace is composed of hyaline cartilage, the most common cartilage, this process tends to be more difficult than intramembranous ossification since all hyaline cartilage most be decomposed as bone tissue is created. Everything begins at the primary ossification center, which is located in the center of diaphysis of the long bone. What set the stage for this process is blood vessels that infiltrate the periosteum, or the covering of the surface of hyaline cartilage composed of dense irregular connective tissue, and vascularize it. The increase in nutrients resulting from near blood vessels cause mesenchymal cells, stems cells of connective tissue, to differentiate, or change into different cells call osteoblasts. Then, the hyaline cartilage model begins to develop a rough covering around the diaphysis of the long bone, the periosteal …show more content…
Osteoclast don’t care that the spongy bone is new; they break it down. As a result, the medullary cavity is formed, it serves as a yellow marrow storage facility. The epiphysis continues to elongate and is composed of hyaline cartilage and its chondroblasts that continue dividing. The bone formation occurs where cartilage is calcified and deteriorates. When a baby is born the diaphysis of most of his or her bones are osteogenic tissue, however, the epiphysis remains as hyaline cartilage. It is not until after birth that the epiphysis develops a secondary ossification center, same as the primary ossification center but in the epiphysis, and more bone is developed. The cartilage in the epiphysis calcifies and dies, which allow periosteal buds to enter. The bone trabecula becomes present and it will store red marrow, used to make blood cells, in the