State about osteogenesis

Embryologically, osteogenesis may be classified as either intramembranous or endochondral. When the ossification occurs directly, it is defined as intramembranous. It is the process by which flat bones like the skull, parts of mandible and clavicle are formed. Embryonic mesenchymal cells with abundant vascular supply develop foci of intracellular collagen deposition. Soon, osteoblasts are identified in these regions, secreting osteoid into which calcium salts are deposited.