notochord


notochord
1. In primitive vertebrates, the primary axial supporting structure of the body, derived from the notochordal or head process of the early embryo; an important organizer for determining the final form of the nervous system and related structures. 2. In embryos, the axial fibrocellular cord about which the vertebral primordia develop; vestiges of it persist in the adult as the nuclei pulposi of the intervertebral discs. SYN: chorda dorsalis. [G. notos, back, + chorde, cord, string]

* * *

no·to·chord 'nōt-ə-.kȯ(ə)rd n a longitudinal flexible rod of cells that in the lowest chordates (as a lancelet or a lamprey) and in the embryos of the higher vertebrates forms the supporting axis of the body, that is almost obliterated in the adult of the higher vertebrates as the bodies of the vertebrae develop, and that arises as an outgrowth from the dorsal lip of the blastopore extending forward between epiblast and hypoblast in the middorsal line
no·to·chord·al .nōt-ə-'kȯrd-əl adj

* * *

n.
a strip of mesodermal tissue that develops along the dorsal surface of the early embryo, beneath the neural tube. It becomes almost entirely obliterated by the development of the vertebrae, persisting only as part of the intervertebral discs.

* * *

no·to·chord (noґto-kord) [noto- + chord] the rod-shaped body, composed of cells derived from the mesoblast of the primitive node of the embryo, defining the primitive axis of the body and acting as the center of development of the axial skeleton; it is the common factor of all species of the phylum Chordata. Called also chorda dorsalis.

Medical dictionary. 2011.

Look at other dictionaries:

  • Notochord — Transverse section of a chick embryo of forty five hours’ incubation. Latin notochorda Gray s …   Wikipedia

  • Notochord — No to*chord, n. [Gr. nw^ton the back + E. chord.] (Anat.) An elastic cartilagelike rod which is developed beneath the medullary groove in the vertebrate embryo, and constitutes the primitive axial skeleton around which the centra of the… …   The Collaborative International Dictionary of English

  • Notochord — Notochord, s. Chorda dorsalis …   Meyers Großes Konversations-Lexikon

  • Notochórd — (grch.), Wirbelsaite, s. Chorda …   Kleines Konversations-Lexikon

  • notochord — (n.) 1848, coined in English by English anatomist Sir Richard Owen (1804 1892) from CHORD (Cf. chord) + comb. form of Gk. noton back, from PIE *not buttock, back (Cf. L. natis buttock, sopurce of It., Sp. nalga, O.Fr. nache buttock, butt ) …   Etymology dictionary

  • notochord — [nōt′ə kôrd΄] n. [ NOTO + CHORD1] 1. an elongated, rod shaped structure composed of cells, forming the primitive supporting axis of the body in the lowest chordates and lying between the digestive tract and the central nervous system 2. a similar …   English World dictionary

  • notochord — notochordal, adj. /noh teuh kawrd /, n. Embryol. a rodlike cord of cells that forms the chief axial supporting structure of the body of the lower chordates, as amphioxus and the cyclostomes, and of the embryos of the vertebrates. [1840 50; NOTO + …   Universalium

  • Notochord — Bauplan eines Lanzettfischchen mit Chorda dorsalis (2) zwischen dem Neuralrohr (1, 3) und dem Kiemendarm (6, 9, 11) Die Chorda dorsalis („Rückensaite“; von lat. chorda bzw. griech. chorde „Darm“, „Darmsaite“ und lat. dorsum „Rücken“), auch… …   Deutsch Wikipedia

  • notochord — the skeletal rod consisting of a sheath firmly packed with cells which lie above the gut and below the nerve cord. The notochord is persistent when it remains as a continuous skeletal support (e.g. Amphioxi, Holocephali, Acipenseridae,… …   Dictionary of ichthyology

  • notochord — noun Etymology: Greek nōton, nōtos back + Latin chorda cord more at cord Date: 1848 a longitudinal flexible rod of cells that in the lowest chordates (as a lancelet or a lamprey) and in the embryos of the higher vertebrates forms the supporting… …   New Collegiate Dictionary

  • notochord — An axial mesodermal tissue found in embryonic stages of all chordates and protochordates, often regressing as maturity is approached. Typically a rod shaped mass of vacuolated cells immediately below the nerve cord, and may provide mechanical… …   Dictionary of molecular biology


Share the article and excerpts

Direct link
Do a right-click on the link above
and select “Copy Link”

We are using cookies for the best presentation of our site. Continuing to use this site, you agree with this.