एक लचीली रॉड जैसा संरचना जो शरीर के सबसे कम chordates और सबसे कम कशेरुकी और उच्च कशेरुकाओं के भ्रूण में शरीर की सहायक धुरी बनाती है

Noun:

उपस्थिमय समूह जो मेरुदंडीय स्‍तंभ बनाते हे, पृष्‍ठरज्‍जु, पृष्‍ठदंड,

notochord's Usage Examples:

The ordinal name for the genera and species of Amphioxus is Cephalochorda, the term referring to the extension of the primary backbone or notochord to the anterior extremity of the body; the family name is Branchiostomidae.

A ventral vessel occurs on the anterior side of the metasome and forms a loop extending down the entire length of the stalk, while a " heart " projects into the cavity of the pericardium, probably connected on the ventral side of the notochord with the ventral vessel, and on its dorsal side with the dorsal vessel.

I, 2), in which the spinal cord rests on the notochord, which persists uninterrupted and is surrounded by three bony elements in addition to the neural arch: a so-called pleurocentrum on each side, which appears to represent the centrum proper of reptiles and mammals, and an intercentrum or hypocentrum below, which may extend to the neural arch, and probably answers to the hypapophysis, as it is produced into chevrons in the caudal region.

a, Cavity surrounding fin ray; a', fin ray; b, muscular tissue of myotome; c, nervecord; d, notochord; c, left aorta; f, thickened ridges of epithelium of praeoral chamber (Rader organ); g, coiled tube lying in a coelomic space on right side of praeoral hood, apparently an artery; h, cuticle of notochord; i, connective-tissue sheath of notochord; k, median ridge of skeletal canal of nerve-cord; 1, skeletal canal protecting nerve-cord; m, inter-segmental skeletal septum of myotome; n, subcutaneous skeletal connective tissue; o, ditto of metapleur (this should be relatively thicker than it is); q, subcutaneous connective tissue of ventral surface of atrial wall (not a canal, as supposed by Stieda and others); r, epiblastic epithelium; s, gonad-sac containing ova; t, pharyngeal bar in section, one of the "tongue" bars alternating with the main bars and devoid of pharyngo-pleural fold and coelom; v, atrio-coelomic funnel; w, socalled "dorsal" coelom; x, lymphatic space or canal of metapleur; y, sub-pharyngeal vascular trunk; z, blood-vessel (portal vein) on wall of hepatic caecum; aa, space of atrial or branchial chamber; bb, ventral groove of pharynx (anteriorly this takes the form of a ridge); cc, hyperbranchial groove of pharynx; dd, lumen or space of hepatic caecum; ee, narrow coelomic space surrounding hepatic caecum; ", lining cell-layer of hepatic caecum; gg, inner face of a pharyngeal bar clothed with hypoblast, the outer face covered with epiblast (represented black); hh, a main pharyngeal bar with projecting pharyngeal fold (on which the reference line rests) in section, showing coelomic space beneath the black epiblast; ii, transverse ventral muscle of epipleura; kk, raphe or plane of fusion of two down-grown epipleura; 11, space and nucleated cells on dorsal face of notochord; mm, similar space and cells on its ventral face.

- anp, Anterior neural pore; be, rudiment of buccal skeleton; c, cilia; cb, ciliated band; cc, ciliated groove; cm, cilia at margin of mouth; gl, external opening of club-shaped gland; Hn, Hatschek's nephridium; lm, left metapleur; n, notochord; pp, praeoral pit; ps, primary gill-slits, I, 5, and 13; rm, right metapleur showing through.

It has, in fact, become metamorphosed into a resistant supporting structure resembling in some respects the notochord of the true Chordata, but probably not directly comparable with the latter structure, being related to it solely by way of substitution.

They are the only pelagic forms that have a notochord and they retain it throughout their lives.

C. Labyrinthodonta, with simple biconcave vertebral disks, very slightly pierced by a remnant of the notochord and supporting the loosely articulated neural arch.

As already stated, the notochord extends beyond the mouth to the tip of the rostrum.

Immediately above the notochord there lies another FIG.

notochord's Meaning':

a flexible rodlike structure that forms the supporting axis of the body in the lowest chordates and lowest vertebrates and in embryos of higher vertebrates

Synonyms:

back, urochord, spinal column, vertebral column, spine, rachis, backbone,

Antonyms:

disapprove, front, fore, anterior, negate,