Josefa Alarcón; Laura García-Orozco; José Villanueva; Jhonatan Duque-Colorado; Ignacio Roa & Mariana Rojas

The vertebral column is the skeletal axis of the body, consisting of 33 vertebrae. Embryologically, vertebral development begins at the end of the third week of gestation and is completed around 25 years of age, when the ossification process concludes. The vertebral body originates from the sclerotome, which derives from the somitic or paraxial mesoderm. Ossification of the vertebral body progresses through three stages: mesenchymal, cartilaginous, and osseous. The mesenchymal stage spans from the fourth to the sixth week. During this stage, the sclerotomal portion of each somite undergoes a process known as resegmentation. The densely packed caudal half of one sclerotome fuses with the loosely arranged cranial half of the adjacent sclerotome segment, forming an intersegmental structure that will eventually develop into the vertebral column. The cartilaginous stage occurs from the sixth to the eighth week, marked by the appearance of six chondrification centers at the level of the vertebral body, costal processes, and neural arches. The osseous stage extends from the tenth intrauterine week to approximately 25 years of age. During this stage, primary and secondary ossification centers develop. The objective of the present work is to present instructional material based on chick embryos and human fetuses at various developmental stages as a contribution to the teaching of Embryology.

ALARCÓN, J.; GARCÍA-OROZCO, L.; VILLANUEVA, J.; DUQUE-COLORADO, J.; ROA, I. & ROJAS, M. Vertebral bodies ossification. Int. J. Morphol., 44(4):1373-1379, 2025.