What is a notochord?

1 Answer
Oct 12, 2016

Notochord is a definitive feature of chordates. It is flexible and cartilaginous and forms during gastrulation.


It extends through out the entire length of the future vertebral column, and reaches as far as the anterior end of the mid brain.

The notochord is primarily composed of glycoproteins, encased in a sheath of collagen fibres wound into two opposing helices.

It is the site of muscle attachment and is a vertebral precursor . It is a midline tissue that also provides signals to the surrounding tissues during development.

In some chordates it persists through out life as the main axial support of the body.
In humans , by the age of 4 , all notochord residue is replaced by chondrocyte like cells.