The notochord (axial mesoderm, notochordal process, chorda dorsalis, Wirbelsäule) is the defining structure forming in all chordate embryos (taxonomic rank: phylum Chordata). It is an early forming midline structure in the trilaminar embryo mesoderm layer initially ventral to the ectoderm, then neural plate and finally neural tube. This is a transient embryonic anatomy structure, not existing in the adult, required for patterning the surrounding tissues. The patterning signal secreted by ... Notochord is a flexible rod-like structure that is found in all chordates. It is similar to cartilage and is involved in signalling and organisation of the nervous system. The notochord usually develops around 16 days after gastrulation from the axial mesodermal cells and is completely formed by the end of the fourth week. The notochord is an embryonic midline structure common to all members of the phylum Chordata, providing both mechanical and signaling cues to the developing embryo. In vertebrates, the notochord ... What is the notochord ? The notochord is the defining structure of the phylum Chordata, which includes all vertebrates. In its ‘mature’ state the notochord is a rod of large cells constrained by a thick extracellular sheath and positioned between the developing spinal cord and gut. Turgor pressure generated by notochord cells exerted against the sheath gives the notochord stiffness, imparting the mechanical properties required for one of its main functions as the central axial skeletal ...
