PhD conferral Mr Hayelom Kebede Mekonen, MSc.

Key words: axial musculo-skeletal system, development

This thesis describes our study of the development of the ventral body wall, the back muscles, and the closure of the vertebral canal in human embryos between 5 and 10 weeks of development. The highlights of the investigation were three novel findings: the ventral body wall forms as a result of exponential growth of the somites in the dorsolateral part of the trunk and (near-)absent growth in the ventral midline; the lateral, intermediate and medial columns of the intrinsic muscles of the back form in that sequence and are duplicated in the neck region and the vertebral canal forms by fusion of the neural processes, beginning in the midthoracic region and extending both cranially and caudally.