Nerve-cord sentence example
- g, Nerve cord.
- In this Annelid later the sac in question joins its fellow, passing beneath the nerve cord exactly as in the leech, and also grows out to reach the exterior.
- - Ventral Muscles and Nerve Cord Cockroach.
- P, Pedal ganglion and commencement of pedal nerve-cord.
- pl, Visceral nerve-cord.Advertisement
- v, Pedal (ventral) nerve-cord.
- 1, Visceral (lateral) nerve-cord.
- v.n, Ventral nerve cord.
- There is a welldeveloped brain dorsal, to the mouth; this gives off a pair of oesophageal commissures, which surround the oesophagus and unite in a median ventral nerve-cord which runs between the longitudinal muscles to the posterior end of the body.
- Strands breaking up the f, Ventral nerve-cord.Advertisement
- b, Ventral nerve-cord.
- There is a single unsegmented nerve-cord which runs along the ventral middle line and enlarges posteriorly into a caudal ganglion and anteriorly in a ganglion, the brain, which is not supra-oesophageal.
- For the sake of uniformity in nomenclature this nerve-cord may be called the neurochord.
- f, Small accessory glandular v.c, Nerve-cord.
- Each of the ventral parts acquires an opening to the exterior, just outside the nerve-cord, G (After Sedgwick.) FIG.Advertisement
- The internal vesicle is already indicated, and is shown in the diagram by the thinner black line: I, gut; 2, somite; 2', nephridial part of coelom; 3, haemocoele; 3', part of haemocoele which will form the heart - the part of the haemocoele on each side of this will form the pericardium; 4, nerve-cord; 4, slime glands.
- - The nervous system in the Hexapoda is built up on the typical arthropodan plan of a double ventral nerve-cord with a pair of ganglia in each segment, the cords passing on either side of the gullet and connecting with an anterior nerve-centre or brain (fig.
- 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.