0The notochord is a midline structure seen in the embryonic period of the human fetus. It acts as a primary organiser and helps to differentiate the surrounding intraembryonic mesoderm into three parts. The paraxial mesoderm is developed into somite under the influence of notochord. Humans are included in chordata due to the presence of notochord in intrauterine life. This is an example of ontogeny repeats phylogeny. Notochord also induces the formation of the neural tube. It remains in the adult as nucleus pulposus at the intervertebral disc. Schmorls node is the bulging of nucleus pulposus leading to nerve compression at that level.
