الفهرس | Only 14 pages are availabe for public view |
Abstract In this study, 48 albino rats of both sexes ranging in age from birth till 90 postnatal days were used. The postnatal development of, the cervical vertebrae were studied by sections and specimens stained with Hex. & E.; Verhocff’s; P.A.5. Reaction and alizarin red 5 stains. The dimensions of the spinal canal were measured using a digital image processing system. This measurement technique introduces many advantages over the classical measurement methods. It is more accurate, reliable and the results are reproducible. There were three primary ossification centers one ventral and two dorsolateral in the vertebral angle. They were separated by three synchondroses, two neurocentral and one dorsal. The axis had two additional centers for the base of the dens. They were separated from the center of the body by dent central synchondroses. The dorsal synchondrosis underwent synostosis at 20 days. The neurocentral and the dent central synchondroses closed at 60 days. As long the synchondroses were open, growth of the vertebrae took place by both transformation and translocation. After 60 days bone growth occurred by apposition and resorption. The measurement showed change in the ratio of the dorsoventral to transverse diameters of the vertebral closure of the dorsal synchondrosis. |