Lecture notes on notochord in embryology

Define notochord: it is the primordial axis of the embryo around which the axial skeleton forms

Formation of notochord

1.      appearance of primitive streak

2.      the cranial end of primitive streak proliferates to form a primitive node

3.      primitive node form the notochordal process , which extends cranially from the primitive node between the embryonic ectoderm and endoderm

4.      a small depression  is developed in the primitive node called primitive pit which extends into the notochordal process and forms notochordal canal.

5.      the notochordal process extends from primitive node to the prechordal plate

6.      opening develop in the floor of the notochordal canal , and the remaining notochordal process flattened and form notochordal plate

7.       the notochordal plate in folds to form the notochord