Question #261
In embryological development:
The notochord, also known as the axial mesoderm, is a rod like structure of mesoderm that signals to the overlying ectoderm to become nervous tissue. During the 3rd to 4th week the neural tissue then starts to fold towards the notochord, forming the neural groove. This happens first in the thoracic region and then progressively cranially and caudally. Failure of this groove to close results in neural tube defects which can be as common as 1 in 300 live births.
Neural crest cells break off from the edges of the neural groove and migrate around the body. Defects in these cells will result in Di George syndrome.
Transplantation of the notochord will result in a second neural tube forming.
The remnant of the notochord forms the nucleus pulposus of the intervertebral discs and the apical ligament between the foramen magnum and C2.