Sep 08, · The notochord is a developmental patterning structure. The only adult anatomy derived from the notochord is the nucleus pulpous of the intervertebral disc. The embryonic notochordal cells are replaced postnatally by fibrocartilage (about 11 years of age). Notochord, flexible rodlike structure of mesodermal cells that is the principal longitudinal structural element of chordates and of the early embryo of vertebrates, in both of which it plays an organizational role in nervous system development. In later vertebrate development, it becomes part of.
The earliest probable species of tunicate appears in the fossil record in the early Cambrian period. Despite their simple appearance and very different adult form, their close relationship to the vertebrates is evidenced by the fact that during their mobile larval stage, they possess a notochord or stiffening rod and resemble a cinedivx.infom: Animalia. The intervertebral disc is a soft tissue, positioned between each of the vertebrae, that accommodates applied biomechanical forces to the spine. The central compartment of the disc contains the nucleus pulposus (NP), which is enclosed by the annulus fibrosus and the endplate cartilage. The NP is Cited by:
notochord A rod-like structure, present in early development, derived from the MESODERM and giving rise to the spine. In the adult, the notochord is represented by the pulpy centres (nucleus pulposus) of the intervertebral discs. Define notochord. notochord synonyms, notochord pronunciation, notochord translation, English dictionary definition of notochord. n. A flexible rodlike structure that is present in the embryos of all chordates and in the adult forms of certain groups, such as the lancelets and Notochord - definition of notochord by The Free Dictionary.