Morphological Study of the Skeleton Development in Chick Embryo (Gallus domesticus)

The study comprised anatomical description of skeleton development in chick embryo Gallud domesticud which includes the appearance of ossification center during the embryological stages (5,10,14, 18 and 21) days. It was found that some of skull bones was formed by intramembranous ossification and that other by endochondral ossification. During the hatching, the skull was undergo complete ossification and there is a symmetry between the paired bones among their shape bone started with primary ossification center. The limbs were formed by endochondral ossification. The ossification begins centrally in the cartilage and proceed in all directions. The hind limbs ossified after fore limbs and there is an ossified signs in the tarsal and carpal bones before hatching. as well as, there is an obvious increases in length of primary ossification centers in both fore and hind limbs with further development. Histologically, three types of bone cells were studied, the osteoblasts, osteocytes and osteoclasts which covered by periosteium and their rules in intramembranous and endochondral ossification.