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Red: notochord; Magenta: axochord; Green: nerve chord; Blue: epidermis; Yellow: mesoderm. The notochord is an elastic, rod-like structure found in chordates. In chordate vertebrates the notochord is an embryonic structure that disintegrates, as the vertebrae develop, to become the nucleus pulposus in the intervertebral discs of the vertebral ...
Both Shh and HNF-3b transcripts are found in the notochord and the floor plate rostral to the node, and they are completely absent in the lateral and caudal neural plate and the primitive streak. In the node proper, the chordin expression pattern is very similar to that of HNF-3b, but more rostrally, chordin is no longer expressed in the floor ...
The notochord plays an integral role in the development of the neural tube. Prior to neurulation, during the migration of epiblastic endoderm cells towards the hypoblastic endoderm, the notochordal process opens into an arch termed the notochordal plate and attaches overlying neuroepithelium of the neural plate. The notochordal plate then ...
Axial mesoderm, or chordamesoderm, is the mesoderm in the embryo that lies along the central axis under the neural tube.. will give rise to notochord; starts as the notochordal process, whose formation finishes at day 20 in humans.
The notochord extends from the base of the head to the tail; with it extend thick bands of paraxial mesoderm. [1] As the primitive streak continues to regress, somites form from the paraxial mesoderm by "budding off" rostrally as somitomeres, or whorls of paraxial mesoderm cells, compact and separate into discrete bodies. The periodic nature of ...
In this way the notochord can be characterized as a hydrostatic organ. [1] During muscle contraction, the notochord also plays an important role in withstanding shortening of the body. [10] The dorsal nerve cord is located behind the notochord. The pharynx is another structure made from cartilage for feeding, found near the throat.
In the 10 somite embryo, Carnegie No. 5074, the prechordal plate is continuous posteriorly with the notochord, and is made up of about 35-40 cells. The prechordal mesenchyme proliferates laterally over the junction of the dorsal aorta and first aortic arch on each side.
In addition, gene expression studies have failed to provide any evidence for homology between the notochord and the stomochord, or between the notochord and any hemichordate structure. The Brachyury (T) gene, which is expressed in the ascidian and other chordates notochord, is not expressed in the stomochord, and collagen is absent. [2]