2. On the Vertebral Column, and some Characters that have been overlooked in the Descriptions both of the Anatomist and Zoologist.

1851 ◽  
Vol 2 ◽  
pp. 166-169
Author(s):  
Macdonald

After noticing that the vertebral skeleton has usually been compared to a column, of which the basis (in man) is formed by the sacrum and coccyx, the shaft or columnar part being the bodies of the true vertebræ, as they are usually styled, and surmounted by the splendid composite capital the cranium, the author proposed restricting the observations to the columnar portion, usually divided into 7 cervical, 12 dorsal, and 5 lumbar vertebræ. This division was denounced, and beginning at the summit, he shewed that the upper or cervical region consisted only of 6 vertebræ, as the 7th, in its normal position in the mammal class, had a rib partly articulated to its body, and therefore acquired the character of a dorsal vertebra.

2017 ◽  
Vol 4 (4) ◽  
pp. 160933 ◽  
Author(s):  
Tomasz Szczygielski

All derived turtles are characterized by one of the strongest reductions of the dorsal elements among Amniota, and have only 10 dorsal and eight cervical vertebrae. I demonstrate that the Late Triassic turtles, which represent successive stages of the shell evolution, indicate that the shift of the boundary between the cervical and dorsal sections of the vertebral column occurred over the course of several million years after the formation of complete carapace. The more generalized reptilian formula of at most seven cervicals and at least 11 dorsals is thus plesiomorphic for Testudinata. The morphological modifications associated with an anterior homeotic change of the first dorsal vertebra towards the last cervical vertebra in the Triassic turtles are partially recapitulated by the reduction of the first dorsal vertebra in crown-group Testudines, and they resemble the morphologies observed under laboratory conditions resulting from the experimental changes of Hox gene expression patterns. This homeotic shift hypothesis is supported by the, unique to turtles, restriction of Hox-5 expression domains, somitic precursors of scapula, and brachial plexus branches to the cervical region, by the number of the marginal scute-forming placodes, which was larger in the Triassic than in modern turtles, and by phylogenetic analyses.


Author(s):  
Martin E. Atkinson

The locomotor system comprises the skeleton, composed principally of bone and cartilage, the joints between them, and the muscles which move bones at joints. The skeleton forms a supporting framework for the body and provides the levers to which the muscles are attached to produce movement of parts of the body in relation to each other or movement of the body as a whole in relation to its environment. The skeleton also plays a crucial role in the protection of internal organs. The skeleton is shown in outline in Figure 2.1A. The skull, vertebral column, and ribs together constitute the axial skeleton. This forms, as its name implies, the axis of the body. The skull houses and protects the brain and the eyes and ears; the anatomy of the skull is absolutely fundamental to the understanding of the structure of the head and is covered in detail in Section 4. The vertebral column surrounds and protects the spinal cord which is enclosed in the spinal canal formed by a large central canal in each vertebra. The vertebral column is formed from 33 individual bones although some of these become fused together. The vertebral column and its component bones are shown from the side in Figure 2.1B. There are seven cervical vertebrae in the neck, twelve thoracic vertebrae in the posterior wall of the thorax, five lumbar vertebrae in the small of the back, five fused sacral vertebrae in the pelvis, and four coccygeal vertebrae—the vestigial remnants of a tail. Intervertebral discs separate individual vertebrae from each other and act as a cushion between the adjacent bones; the discs are absent from the fused sacral vertebrae. The cervical vertebrae are small and very mobile, allowing an extensive range of neck movements and hence changes in head position. The first two cervical vertebrae, the atlas and axis, have unusual shapes and specialized joints that allow nodding and shaking movements of the head on the neck. The thoracic vertebrae are relatively immobile. combination of thoracic vertebral column, ribs, and sternum form the thoracic cage that protects the thoracic organs, the heart, and lungs and is intimately involved in ventilation (breathing).


2013 ◽  
Vol 9 (5) ◽  
pp. 20130486 ◽  
Author(s):  
William T. Stanley ◽  
Lynn W. Robbins ◽  
Jean M. Malekani ◽  
Sylvestre Gambalemoke Mbalitini ◽  
Dudu Akaibe Migurimu ◽  
...  

The hero shrew's ( Scutisorex somereni ) massive interlocking lumbar vertebrae represent the most extreme modification of the vertebral column known in mammals. No intermediate form of this remarkable morphology is known, nor is there any convincing theory to explain its functional significance. We document a new species in the heretofore monotypic genus Scutisorex ; the new species possesses cranial and vertebral features representing intermediate character states between S. somereni and other shrews. Phylogenetic analyses of DNA sequences support a sister relationship between the new species and S. somereni . While the function of the unusual spine in Scutisorex is unknown, it gives these small animals incredible vertebral strength. Based on field observations, we hypothesize that the unique vertebral column is an adaptation allowing these shrews to lever heavy or compressive objects to access concentrated food resources inaccessible to other animals.


2003 ◽  
Vol 81 (11) ◽  
pp. 1851-1861 ◽  
Author(s):  
Anders Galatius ◽  
Carl Christian Kinze

The onset and timing of epiphyseal ankylosis in the vertebral column and flippers and ankylosis of the hyoid and sternal bones were studied in 350 skeletons of the harbour porpoise (Phocoena phocoena) originating from the Baltic and North Sea and held in the collections of the Zoological Museum (University of Copenhagen), the Museum of Natural History (Gothenburg), the National Museum of Natural History (Stockholm), and the German Oceanographic Museum (Stralsund). Epiphyseal ankylosis in the vertebral column started in the anterior cervical region and then initiated around the 23rd to 26th caudal vertebrae from where it proceeded in both directions. The progression of vertebral epiphyseal ankylosis eventually terminated in the thoracic and lumbar regions. Epiphyseal ankylosis in the flippers began at the distal end of the humerus and the proximal ends of the radius and ulna. The timing of ankylosis in the flippers was more consistent across the specimens than the timing of vertebral ankylosis. Males and females had similar timing of ankylosis in the vertebral column and the flippers. Complete fusion of the hyoid and sternal bones occurred within the first year of life in most specimens. The early development of the hyoid apparatus may be linked to use of suction in feeding.


Development ◽  
1992 ◽  
Vol 115 (2) ◽  
pp. 487-501 ◽  
Author(s):  
M. Kessel

In higher vertebrates, the formation of the body axis proceeds in a craniocaudal direction during gastrulation. Cell biological evidence suggests that mesoderm formation and specification of axial positions occur simultaneously. Exposure of gastrulating embryos to retinoic acid induces changes in axial patterns, e.g. anterior and posterior homeotic transformations of vertebrae. These morphological changes are accompanied by changes in the nonidentical, overlapping expression domains of Hox genes. In this report the influence of retinoic acid, administered at the end of and after gastrulation, on vertebral patterns is described. Anterior transformations and truncations affecting the caudal part of the vertebral column characterize animals exposed on day 8 and 9. 4 hours after retinoic acid administration on day 8 + 5 hours, Hox-1.8, Hox-1.9, and Hox-4.5 transcripts were not detected in their usual posterior expression domains, whereas transcripts of the anterior Hox-1.5 gene remained unaffected. 4 days after RA exposure on day 8 + 5 hours, Hox-1.8 expression was shifted posteriorly by an effectively low dose of RA, which induced the formation of supernumerary ribs. Hox-1.8 expression was limited to posterior, disorganized mesenchyme, bulging out neural tube, some intestinal loops and the hindlimb in truncated embryos exposed to a high dose of RA. A causal relation between the delayed activation of posterior Hox genes and anterior transformations or agenesis of vertebrae is discussed. On day 10.5 posterior transformations begin to occur in the cervical region, while later exposures again affect more caudal structures. The distribution of the transformations along the vertebral column indicates an influence of RA on migrating sclerotome cells before they are finally fixed in the cartilagenous vertebrae. The findings show that the mesodermal segments originally specified during gastrulation can be respecified in their second migratory phase, with effects spreading for a second time in a craniocaudal direction. The transformations are discussed with regard to a molecular specification of axial levels by Hox codes, defined as combinations of expressed Hox genes.


Author(s):  
P. Sridevi ◽  
K. Rajalakshmi ◽  
M. Sivakumar ◽  
A. Karthikeyan

Background: Indian eagle owl known to rotate their necks up to 270 degrees in either direction without injuring their vessels running below the head thereby without cutting off blood supply to their brains. The vertebral column in birds carry peculiar features like higher number of cervical vertebrae due to long mobile neck, lumbar and sacral vertebrae fused together giving rigidity which aid in flight. The extensive fusion of vertebral column posterior to the neck provides the required rigidity in the trunk region, this inflexibility feature might reduce weight, as it avoids the need for extensive musculature to maintain a streamlined and rigid body posture during flight. The current study aimed to study the vertebral column of Indian eagle owl in order to understand the anatomical adaptations related to this species. Methods: The specimens were procured from three Indian eagle owl brought for post mortem examination during the year 2019 to the Department of Veterinary Pathology, Rajiv Gandhi Institute of Veterinary Education and Research, Puducherry. After completion of the post-mortem examination the carcass was collected and macerated as per the standard technique and various measurements on vertebral column bones were measured using vernier calliper. Result: The study revealed that vertebral column of Indian eagle owl consisted of 14 cervical vertebrae, 7 thoracic vertebrae, 13 to 14 lumbar vertebrae fused with sacral vertebrae forming synsacrum and 7 coccygeal vertebrae. The hypapophyses of the 14th cervical vertebra and first two thoracic vertebrae were trifid in nature specific feature seen in Indian eagle owl. The vertebral column had characteristics features of hypapophyses, transverse process, pneumatic foramen and neural spine which enable the owl to adapt for head rotation and various task involving vertebrae.


Author(s):  
Cosmin PEŞTEAN ◽  
Liviu OANA ◽  
Cristian CRECAN ◽  
Alexandra MUREŞAN ◽  
Robert PURDOIU ◽  
...  

The aim of this study was to establish a specific interdisciplinary protocol for evaluation of horses with spinal cord compression. A filly was presented with signs of ataxia at the Faculty of Veterinary Medicine Cluj-Napoca. After neurological examination the presumptive diagnostic was spinal cord compression. Under general anesthesia, the patient was placed for radiological examination in lateral recumbency with head elevated. After antisepsia of cervical region, a Tuohy needle was inserted in atlanto-occipital space and contrast substance was administrated. Radiographic images of the cervical vertebral column were obtained in the neutral, flexed, and extended head positions. The anesthesia protocol was effective, the needle was placed safely in the subarachnoid space and the contrast substance flowed caudally. The obtained radiographic images confirmed spinal cord compressions at the level of cervical vertebrae C3, C4, C5. This working protocol was effective to obtain radiographical images with contrast substance in horses with neurological diseases.


2012 ◽  
Vol 93 (1) ◽  
pp. 44-48
Author(s):  
A B Tomilov ◽  
N L Kuznetsova

Aim. To improve the results of treatment of patients with post-traumatic deformity of the vertebral column. Methods. Analyzed were the results of treatment of 400 patients with fractures of the thoracic and lumbar vertebrae. Lesions of types A2, A3 and B according to the classification of the Association of osteosynthesis were seen in 70% of cases, lesions of type C - in 30%. The external transpedicular «Crab» construction was used in 100 patients. An internal transpedicular construction of the Scientific Research Institute «Syntez» was used in 300 cases. Transpedicular spondylosynthesis with intraoperative correction of the deformity with an original repositioning device was performed in all patients. Explosion fractures with the destruction of the vertebral body and stenosis of the spinal canal demanded the implementation of decompressive-stabilizing interventions in 25% of the cases. Conducted were clinical and radiological (spondylography, computed tomography, magnetic resonance imaging) studies. Results. Proposed was a technique of guided correction of posttraumatic deformities of the vertebral column. Unstable fractures and dislocation-fractures, lesions of intervertebral discs in the thoracic and lumbar segments of the vertebral column, inveterate lesions, posttraumatic deformities of the thoracic and lumbar segments of the vertebral column served as indications for using guided correction. Kyphotic deformity at the level of the damaged segment was corrected in 98% of observed cases with hypercorrection in the range of 2°. The vertical size of the vertebral body was restored up to 100% in the early posttraumatic period and up to 82.3% in the remote posttraumatic period. Subluxation was corrected in 86.9%, while dislocation of the fractured vertebra was corrected in 96.7% of cases. Conclusion. The proposed method of correction of posttraumatic deformities of the vertebral column makes it possible to provide similar treatment results of patients operated both with using the external fixation device of the vertebral column «Crab» and using the submersible transpedicular construction of the Scientific Research Institute «Syntez».


Author(s):  
Elizabeth Weiss

Stress fractures (or fatigue fractures) are covered in this chapter. Stress fractures are assumed to occur due to microcracks from repetitive forces that accumulate to result in a complete bone break, but these fractures can result from a single traumatic event. The most common location for stress fractures is the vertebral column; two common vertebral stress fractures include spondylolysis and clay-shoveler’s fractures. Spondylolysis fractures, which occur on the lumbar vertebrae, are the most often reported stress fractures. Non-activity causes of stress fractures and the closely related stress hernias, called Schmorl’s nodes, have been found in twin studies; these fractures and hernias seem to be correlated with normal anatomical variation found in the vertebral column. These anatomical variations are likely determined by genes.


1992 ◽  
Vol 6 ◽  
pp. 228-228
Author(s):  
Charlotte Otts

Phenacodus vortmani and P. primaevus, members of the mammalian radiation (Tiffanian - Bridgerian) in western North America, were digitigrade five-toed ungulates who were good runners compared to their contemporaries. P. vortmani was smaller and more slender (presacral vertebral column = 463 mm) while P. primaevus was larger and more robust (presacral vertebral column = 814 mm).The presacral vertebral column in these phenacodontids consists of 7 cervical, 15 thoracic, and 6 lumbar vertebrae, with the sectional length proportions being very similar in P. vortmani and P. primaevus.Morphologies and relationships of the vertebral structure in the cervical section allow both dorsoventral and mediolateral movements in both animals. Structures in the cranial thoracic section allow some mediolateral movement but restrict dorsoventral motion, adding stability and allowing forward transfer of momentum generated in the hind limb and caudal vertebral column. Structures in the caudal thoracic and especially the lumbar sections allow greater dorsoventral movements which enabled both phenacodontids to increase stride length beyond that accomplished by the limbs alone. In the smaller P. primaevus. the orientation of the zygapophyses emphasizes dorsoventral movements and restricts mediolateral movements compared to that in P. vortmani. providing the larger animal with greater efficiency in the flexion and extension of the posterior vertebral column during running.


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