(n.) 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 vertebrae and the posterior part of the base of the skull are developed; the chorda dorsalis. See Illust. of Ectoderm.
Example Sentences:
(1) The histochemical study of the LDH in the Trout embryo during the early organogenesis shows a specific localization in notochord cells, in mesodermic cells of the terminal knob and in some prosencephalic neuroblasts.
(2) The notochord, which is composed of a stack of flat cells surrounded by a connective tissue sheath, elongates dramatically and begins straightening between stages 21 and 25.
(3) Autoradiographic studies show that tritiated proline is taken up by notochordal cells and secreted to the extracellular space where label is associated with basal lamina, microfibrils and ground substance.
(4) Metabolic events in somites related to hyaluronic acid are not influenced by the notochord.
(5) The establishment of myeloschisis was followed by local separation of the notochord from an open area of neural tube, but not by overgrowth of neural tissue.
(6) By 7 days, notochordal uptake is markedly diminished, and no uptake of isotope occurs from 8 days onward.
(7) It first forms on the lateral portion of the neuroepithelium of the neural folds and then extends ventrally into the region adjacent to the notochord; (ii) BL becomes continuous beneath the epidermal ectoderm (EE) that overlies the NC cell region only during the terminal stages of NC cell emigration; (iii) BL does not form over the dorsal portion of the neural tube until NC emigration is terminated; and (iv) the morphology of the BL changes as development proceeds.
(8) Although they are presumed to arise from congenital notochordal remnants, it is rare for these tumors to present in childhood.
(9) Six chordomas, ten fetal notochords and eight adult notochords were stained for keratin, vimentin, GFAP, desmin, CEA, EMA and s-100 protein.
(10) A "diffuse pattern" that was seen in the histological appearance of 4 cases of the chordoma, including 2 cases with metastases, was not observed in the notochord and was considered to indicate the malignant nature of such chordoma.
(11) The results lead to the assumption that the early embryos already possess cholinergic receptors, probably located in the notochord.
(12) Adjacent to the caudal half of each somite, these cells penetrated no further than the myosclerotomal border, but opposite the rostral somite half, they were found next to the sclerotome almost as far ventrally as the notochord.
(13) These results indicate that 1) Engrailed-2 expression is suppressed in the most ventral neural tube owing to induction of the floor plate by the notochord, and 2) that the presence of an underlying notochord is not required for correct rostrocaudal expression, suggesting that multiple pathways act in the patterning of the rudiment of the central nervous system.
(14) Neural induction through the presumptive notochord was tested by means of the sandwich method.
(15) The notochord and neural tube are well developed by 3 days and surrounded by sclerotome, myotome, and dermatome cells.
(16) Minute fragments of the notochord of Balanoglossus sp.
(17) Glycosaminoglycans (GAG) are found primarily in the dorsal fin and in the ECM surrounding the notochord.
(18) Based on these facts, it is to be concluded that it is not the inducer of notochord, but the surrounding mesenchyme that is of primary importance for the determination of the types of neural tissue.
(19) A floor plate-specific chemoattractant was used as a marker to examine the role of the notochord in avian floor plate development.
(20) 2G9 was used to show that both notochord and somites are capable of neural induction, and the stimulus is present as late as stage 22.
Spine
Definition:
(n.) A sharp appendage to any of a plant; a thorn.
(n.) A rigid and sharp projection upon any part of an animal.
(n.) One of the rigid and undivided fin rays of a fish.
(n.) The backbone, or spinal column, of an animal; -- so called from the projecting processes upon the vertebrae.
(n.) Anything resembling the spine or backbone; a ridge.
Example Sentences:
(1) Univariate and multivariate analyses indicated previous LBP or back pain in another location of the spine were strongly associated with LBP during the study year.
(2) In contrast, the ryanodine receptor is observed in dendritic shafts, but not in the spines.
(3) We reviewed the results of intraoperative monitoring of short-latency cortical evoked potentials in 81 patients who underwent surgical procedures of the cervical spine.
(4) Unrecognized flexion injuries of the cervical spine may lead to late instability and neurologic damage.
(5) The present case indicates that the possibility of osseous spines impinging on the facial nerve should be considered in all cases of facial spasm.
(6) The results of conventional sciatic nerve stretching tests are usually evaluated regardless of patient age, gender or movements of the hip joint and spine.
(7) The correlation of posterior intervertebral (facet) joint tropism (asymmetry), degenerative facet disease, and intervertebral disc disease was reviewed in a retrospective study of magnetic resonance images of the lumbar spine from 100 patients with complaints of low back pain and sciatica.
(8) Lumbosacral spine films revealed only minimal degenerative changes, while lumbar myelogram showed L4-L5 and L5-S1 ventral extradural defects.
(9) This paper presents a comparison of the diagnostic value of CT studies and conventional radiological diagnosis, based on 46 CT studies, in patients with inflammatory bone lesions of the spine (n = 20) before and after surgical interventions (n = 12).
(10) Specimens from the bone marrow taken were by trephine biopsy from the sternum, ala ossis ilii and spine.
(11) Quite the contrary, in cases of higher nervous activity disturbances, destruction of the organelles and desintegration of spine apparatuses is clearly pronounced.
(12) The left scapula in each dog was treated by open reduction and plating of the scapular spine.
(13) In general, the cerebellum showed a much delayed developmental pattern with regard to Purkinje cell spine formation.
(14) The effects exerted on the cervical spine by a traction of 150 N was studied by means of an improved radiographic technique.
(15) In the perineuronal neuropil of large pyramidal neurons (layers V-VI) there appear symmetric synapses with pyramidal cells, dendritic processes and dendritic spines.
(16) For conservative treatment of injuries of the cervical spine, two different methods are available: The HALO fixator and the collar.
(17) Whereas in flexion stress all methods showed a sufficient stability, the rotation tests proved, that in case of a dorsal instability of the lower cervical spine, posterior interlaminar wiring or anterior plate stabilization showed no reliable stabilization effect.
(18) Recommendations are made suggesting closer scrutiny of this region of the spine.
(19) Differentiation from synovial or ganglion cysts of the spine is discussed.
(20) To avoid the complications attributable to the cervical spine, we recommend roentgenographic examination in all neurofibromatosis patients who are about to have general anesthesia or skull traction for treatment of scoliosis.