scholarly journals Functional cervicothoracic boundary modified by anatomical shifts in the neck of giraffes

2016 ◽  
Vol 3 (2) ◽  
pp. 150604 ◽  
Author(s):  
Megu Gunji ◽  
Hideki Endo

Here we examined the kinematic function of the morpho- logically unique first thoracic vertebra in giraffes. The first thoracic vertebra of the giraffe displayed similar shape to the seventh cervical vertebra in general ruminants. The flexion experiment using giraffe carcasses demonstrated that the first thoracic vertebra exhibited a higher dorsoventral mobility than other thoracic vertebrae. Despite the presence of costovertebral joints, restriction in the intervertebral movement imposed by ribs is minimized around the first thoracic vertebra by subtle changes of the articular system between the vertebra and ribs. The attachment area of musculus longus colli , mainly responsible for ventral flexion of the neck, is partly shifted posteriorly in the giraffe so that the force generated by muscles is exerted on the cervical vertebrae and on the first thoracic vertebra. These anatomical modifications allow the first thoracic vertebra to adopt the kinematic function of a cervical vertebra in giraffes. The novel movable articulation in the thorax functions as a fulcrum of neck movement and results in a large displacement of reachable space in the cranial end of the neck. The unique first thoracic vertebra in giraffes provides higher flexibility to the neck and may provide advantages for high browsing and/or male competition behaviours specific to giraffes.

Author(s):  
Martin E. Atkinson

The surface anatomies of the face and neck and their supporting structures that can be palpated have been described in Chapter 20. It is now time to move to the structures that lie under the skin but which cannot be identified by touch starting with the neck and moving up on to the face and scalp. The cervical vertebral column comprises the seven cervical vertebrae and the intervening intervertebral discs. These have the same basic structure as the thoracic vertebrae described in Section 10.1.1. Examine the features of the cervical vertebra shown in Figure 23.1 and compare it with the thoracic vertebra shown in Figure 10.3. You will see that cervical vertebrae have a small body and a large vertebral foramen. They also have two distinguishing features, a bifid spinous process and a transverse foramen, piercing each transverse process; the vertebral vessels travel through these foramina. The first and second vertebrae are modified. The first vertebra, the atlas, has no body. Instead, it has two lateral masses connected by anterior and posterior arches. The lateral masses have concave superior facets which articulate with the occipital condyles where nodding movements of the head take place at the atlanto-occipital joints. The second cervical vertebra, the axis, has a strong odontoid process (or dens because of its supposed resemblance to a tooth) projecting upwards from its body. This process is, in fact, the body of the first vertebra which has fused with the body of the axis instead of being incorporated into the atlas. The front of the dens articulates with the back of the anterior arch of the atlas; rotary (shaking) movements of the head occur at this joint. The seventh cervical vertebra has a very long spinous process which is easily palpable. The primary curvature of the vertebral column is concave forwards and this persists in the thoracic and pelvic regions. In contrast, the cervical and lumbar parts of the vertebral column are convexly curved anteriorly. These anterior curvatures are secondary curvatures which appear in late fetal life. The cervical curvature becomes accentuated in early childhood as the child begins to support its own head and the lumbar curve develops as the child begins to sit up.


2018 ◽  
Vol 63 (No. 3) ◽  
pp. 131-136
Author(s):  
S. Lim ◽  
J. Jeong ◽  
HG Heng ◽  
S. Sung ◽  
Y. Choi ◽  
...  

There are several reports in the veterinary literature on tracheal assessment; however, there is a lack of studies on the trachea in voluntarily breathing dogs. The aim of this study was to describe the natural shape of the trachea in awake dogs and to assess tracheal dimensions and the width-to-height ratio. Thoracic computed tomographic images of awake small breed dogs without any signs of respiratory malfunction (n = 19) were evaluated. Each trachea was categorised into one of four different shapes: circular, horseshoe, crescent or focal dorsal invagination. The circular shape was prominent, particularly in the thoracic inlet and intrathoracic area, while the horseshoe shape was also normally present. In this group of normal dogs, there were no crescent-shaped tracheas, but focally invaginated tracheas were observed. The mean tracheal heights at five locations, namely the caudal endplate of the fourth cervical vertebra, cranial endplate of the seventh cervical vertebra, mid-body of the first thoracic vertebra, mid-body of the third thoracic vertebra, and 1 cm cranial to the carina were 9.12, 8.96, 9.34, 9.88 and 10.16 mm, respectively. The widths at these same sites were 12.26, 10.42, 10.07, 9.82 and 10.23 mm, respectively. The width-to-height ratios of each tracheal location were 1.38, 1.20, 1.10, 1.01 and 1.03, the last two of which are consistent with the circular shape of the intrathoracic trachea. Multi-detector computed tomography under non-general anaesthesia is a non-invasive and unparalleled imaging tool for describing tracheal appearance in healthy awake dogs.


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.


2019 ◽  
Vol 100 (4) ◽  
pp. 622-628
Author(s):  
I A Men’shchikova

Aim. To reveal the patterns of the changes of osteometric characteristics of the adults living in the Ural region. Methods. 56 cadavers of human beings at the age of maturity were analyzed (28 women aged 21 to 55 years, and 28 men aged 22 to 60 years) being the residents of the Ural region. The scheme recommended by the Symposium on Age Periodization at the Institute of Age Physiology in 1969, was used for distribution by age groups. Osteometry and statistical method were used. Results. In the cervical spine, the greatest sagittal size was determined in the spinal process of the VII cervical vertebra (30.9±1.79 mm), in the thoracic spine — in the VII thoracic vertebra (41.5±2.4 mm), and in lumbar spine — in the III lumbar vertebra (36.4±0.95 mm). The frontal size of vertebral bodies increased from overlying vertebrae to underlying ones, however, the decrease in the frontal size of vertebral bodies was noted from the I thoracic to the VI thoracic vertebra, and starting from the VII thoracic vertebra its further increase was observed. The sagittal size of vertebral body increased only from the II cervical vertebra to the III lumbar one. The sagittal size of the bodies of the III–V vertebrae was within the range of 32–34 mm. The sizes of vertebral arch pedicle allow conducting the transpedicular fixation at the level of all vertebrae, but it should be taken into account that in V and VI thoracic vertebrae frontal size of arch pedicle is the least as compared to other levels. The frontal sizes of spinal canal were more than sagittal ones at the levels of all vertebrae, with the exception of atlas and the V thoracic vertebra. Conclusion. The results can serve as the basis for performing any surgical interventions on the spine and as the norm for evaluation of its pathological changes.


2006 ◽  
Vol 56 (1) ◽  
pp. 63-68 ◽  
Author(s):  
Sebastiaan Ruinard ◽  
Frans Helmerhorst ◽  
Jurien De Koning ◽  
Marc Steigenga ◽  
Ans Tijssen ◽  
...  

AbstractThe presence of a rib on the seventh cervical vertebra (a cervical rib) represents one of the most common intraspecific variations of the number of cervical vertebrae in mammals. Cervical ribs are highly associated with stillbirths, congenital abnormalities and embryonal tumours. These associations indicate strong stabilising selection against such a change to the highly conserved number of cervical vertebrae in humans. We propose, therefore, that the presence of variation for this highly conserved trait can be used as an indicator of medical risks. We have tested for prolonged effects of controlled ovarian hyperstimulation treatments (OHS) in mice by analysing the frequency of cervical ribs in the offspring of females that had received OHS treatment. We found that OHS treatment in mice had several significant effects on the offspring after adjusting for multiple pregnancy: these included an increase in cervical rib incidence, gestational period and nest size, and a decrease in birth weight and ossification, indicating growth retardation.The high incidence of cervical ribs in the OHS group compared to the control group (39.5% vs. 4.7%) indicates that the OHS treatment affects embryogenesis during a period that is highly sensitive to disturbance, the early organogenesis stage (phylotypic stage). This implies that in mice OHS treatment of the mother has a prolonged effect and continues during early pregnancy.


2016 ◽  
Vol 30 (2) ◽  
pp. 284-288
Author(s):  
N. Saba ◽  
A. Rani ◽  
G. Sehgal ◽  
Rk Verma ◽  
Ak Srivastava ◽  
...  

Abstract Introduction: Fusion of one or more contiguous vertebral segments is usually the result of embryological failure of normal spinal segmentation. It may be associated with syndromes such as Klippel-Feil. Fused cervical vertebrae (FCV) may also be acquired or pathologic. FCV is generally associated with disease like tuberculosis, other infections, juvenile rheumatoid arthritis and trauma. The commonest site of involvement is C2-C3. In condition of fusion the two vertebrae appear not only structurally as one but also function as one. This anomaly may be asymptomatic; however, it may also manifest in the form of serious clinical features such as myelopathy, limitation of the neck movement, muscular weakness, atrophy or neurological sensory loss. Case report: We observed the fusion of axis with 3rd cervical vertebra. Body, laminae and spines of C2 and C3 were completely fused on both anterior and posterior aspects, whereas the pedicles and transverse processes were not fused. Foramen transversarium was present on both the vertebrae bilaterally. Conclusion: This variation is noteworthy to neurosurgeons and radiologists in studying computed tomography (CT) and magnetic resonance imaging (MRI) scans.


Author(s):  
Seyed Reza Saadat Mostafavi ◽  
Azadeh Memarian ◽  
Omid Motamedi ◽  
Arash Heidari

Background: The cervical vertebrae are more durable than other skeletal components, and maybe the only remains of a deceased, and their role in determining the height of the deceased has been underestimated. The present study investigated the role of linear differential dimensions of the seventh cervical vertebrae in determining the height of the Iranian adult population using CT scans.Methods: In this cross-sectional study, height were evaluated by 10 indices of the seventh cervical vertebra. The indices were obtained through a CT scan of 66 adult patients, ≥18 years of age, who referred to Rasoul Akram and Firoozgar hospitals for spine CT scan. The sampling method was random, and the study was performed during the first six months of 2018. Results: Four indices of the Length of the Inferior Facets) LIF, (Length of the Inferior Surface of the Vertebral Body) LIVB, (Width of the Inf surface of the Vertebral Body) WIVB, (Length of Spinous Process ) LSP. were statistically significant differences.Conclusion: The results of this study show the accuracy of linear dimensions of the seventh cervical vertebrae for determining height from skeletal remains in the Iranian adult population.


2013 ◽  
Vol 03 (04) ◽  
pp. 097-099 ◽  
Author(s):  
Pretty Rathnakar ◽  
Remya K. ◽  

AbstractThe cervical vertebrae presents foramen transversaria in each transverse process. In all but the seventh cervical vertebra, the foramen normally transmits vertebral artery and vein and a branch from the cervicothoracic ganglion.140 cervical vertebrae were studied. Variations were noticed in the number of foramen transversarium unilaterally and bilaterally. Variations in foramen transversarium may indicate the variation in course of vertebral arteries


Sensors ◽  
2021 ◽  
Vol 21 (11) ◽  
pp. 3849
Author(s):  
Martin Svoboda ◽  
Milan Chalupa ◽  
Karel Jelen ◽  
František Lopot ◽  
Petr Kubový ◽  
...  

The article deals with the measurement of dynamic effects that are transmitted to the driver (passenger) when driving in a car over obstacles. The measurements were performed in a real environment on a defined track at different driving speeds and different distributions of obstacles on the road. The reaction of the human organism, respectively the load of the cervical vertebrae and the heads of the driver and passenger, was measured. Experimental measurements were performed for different variants of driving conditions on a 28-year-old and healthy man. The measurement’s main objective was to determine the acceleration values of the seats in the vehicle in the vertical movement of parts of the vehicle cabin and to determine the dynamic effects that are transmitted to the driver and passenger in a car when driving over obstacles. The measurements were performed in a real environment on a defined track at various driving speeds and diverse distributions of obstacles on the road. The acceleration values on the vehicle’s axles and the structure of the driver’s and front passenger’s seats, under the buttocks, at the top of the head (Vertex Parietal Bone) and the C7 cervical vertebra (Vertebra Cervicales), were measured. The result of the experiment was to determine the maximum magnitudes of acceleration in the vertical direction on the body of the driver and the passenger of the vehicle when passing a passenger vehicle over obstacles. The analysis of the experiment’s results is the basis for determining the future direction of the research.


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