On vertebral body growth.

We have studied development of vertebral bodies with special regard to the area of contact of the vertebral body with the intervertebral disc. We have investigated complete serial sections of fetuses of the 2nd to 3rd month of intrauterine life, microscopic preparations from children, adolescents and young adults. The results of our studies and deductions from our findings are as follows: 1. Cartilaginous plates on contact surfaces of vertebral bodies with intervertebral discs are genetically parts of vertebral bodies, not of the discs. 2. During ontogenesis and growth period of life typical growth (epiphyseal) cartilages with all layers described on growth cartilages of long bones are formed on the surface of these cartilaginous plates facing the vertebral bodies. 3. From the point of view of its growth, the vertebral body should be considered to be a long bone. 4. Unlike other long bones of the skeleton, vertebral body epiphyses never ossify, and after the end of the growth period of life they are reduced into thin plates of hyaline cartilage which are situated between vertebral body and intervertebral disc. 5. We assume nucleus pulposus is not a persistent residuum of notochord. 6. According to our findings the link of sacral vertebral segments is from the very beginning of development typical synchondrosis with bipolar physes without formation of primordium of intervertebral disc.