The Skeleton of Giraffes

2021 ◽  
pp. 342-381
Author(s):  
Graham Mitchell
Keyword(s):  
Cervical Vertebrae ◽  
Lumbar Vertebrae ◽  
Average Density ◽  
Cross Sectional Area ◽  
Thoracic Vertebrae ◽  
Sectional Area ◽  
Average Chemical Composition ◽  
Cross Sectional ◽  
Limb Bones ◽  
The Difference

The giraffe skeleton consists of ~170 bones. The dry mass of the skeleton is 70 g.kg-1 body mass. The average chemical composition of their bones is 33% minerals (mainly calcium and phosphorus in a ratio of 2:1), 34% collagen, and 33% water. The skull contributes ~10%, the vertebrae ~25% and the limb bones ~65% to skeleton mass. The average density of all bones is 1.6 g cm-3, ranging from 0.8 g cm-3 (cervical vertebrae) to 2.0 g cm-3 (limb bones). Resistance to fracture by vertebrae depends on their cross-sectional area, and is greatest in cervical and the first few thoracic vertebrae. Resistance to fracture by limb bones depends on wall thickness (the difference between inner and outer diameter), which is uniquely thick. The growth of all limb bones except the humerus follows a geometric pattern (length and diameter increase at the same rate) which confers resistance to compression stress. The humerus follows an elastic pattern (diameter increases faster than length) a pattern that resists bending stress. Giraffes bones are exceptionally straight which further reduces bending stresses. The torque generated by the mass of the head and neck is resisted by the ligamentum nuchae which is exceptionally well-developed in giraffes, extends from the lumbar vertebrae to the occipital crest, can have a diameter of ~10 cm, and can support loads of ~1.8 tonnes before rupturing. As a giraffe grows muscle cross-sectional area (and contraction strength) declines and the duty factor reduces, both of which reduce the risk of fracture.

scholarly journals Comparison of Muscle Cross-sectional Area and Lumbar Muscle Strength According to Degenerative Spinal Diseases

2020 ◽  
Vol 22 (2) ◽  
pp. 1-10
Author(s):  
Ji-Hoon Cho ◽  
Ki-Hyuk Lee ◽  
Seung-Taek Lim ◽  
Buong-O Chun
Keyword(s):  
Muscle Strength ◽  
Cross Sectional Area ◽  
Spinal Diseases ◽  
Sectional Area ◽  
Multifidus Muscle ◽  
Cross Sectional ◽  
Total Group ◽  
Male Group ◽  
The Difference ◽  
Lumbar Extension

OBJECTIVES The purpose of this study was to investigate the difference in the cross - sectional area (CSA) of multifidus and Iliopsoas muscles and the lumbar extension muscle strength according to degenerative spinal diseases (LHI; lumbar herniation of intervertebral disc group, SS; spinal stenosis group, S; spondylolisthesis group).METHODS The CSA of multifidus and Iliopsoas muscles size were measured by PACS(Picture Achiving and Communication System) using MRI at the L4/5 level and lumbar extension muscle strength (72˚, 60˚, 48˚, 36˚, 24˚, 12˚, 0˚) was measured using lumbar extension machine(MedX) in 97 patients of degenerative spinal diseases(male: 57, female: 40). The collected data were analyzed by one-way ANOVA using the SPSS program.RESULTS The results of this study showed that the CSA of total and right multifidus muscle in the LHI was significantly higher than that of the S (p <.05; p <.05) in the male group. The difference between the left and right CSA of multifidus in the LHI group was significantly higher than that of the SS (p <.05) in the male group (p <.05) and total group (p <.05). The CSA of iliopsoas muscle in the S was significantly higher than that of the LHI in the male and total group (p <.05; p <.05). In case of lumbar extension muscle strength, the S showed significantly higher muscle strength at 36 and 48 degrees than that of the SS in the male group. In the total group, LHI showed significantly higher muscle strength at 60 degrees of lumbar extension muscle strength than that of the S.CONCLUSION Multifidus muscle appears to be a key factor in prevention and treatment intervention in low back pain patients. In particular, in the case of S group, exercise therapy for strengthening the multifidus muscle is need for the rehabilitation.

Maintenance of myonuclear domain size in rat soleus after overload and growth hormone/IGF-I treatment

1998 ◽  
Vol 84 (4) ◽  
pp. 1407-1412 ◽  
Author(s):  
G. E. McCall ◽  
D. L. Allen ◽  
J. K. Linderman ◽  
R. E. Grindeland ◽  
R. R. Roy ◽  
...  
Keyword(s):  
Growth Hormone ◽  
Domain Size ◽  
Cross Sectional Area ◽  
Sectional Area ◽  
Muscle Weight ◽  
Cross Sectional ◽  
Igf I ◽  
Myonuclear Domain ◽  
The Difference ◽  
Saline Vehicle

The purpose of this study was to determine the effects of functional overload (FO) combined with growth hormone/insulin-like growth factor I (GH/IGF-I) administration on myonuclear number and domain size in rat soleus muscle fibers. Adult female rats underwent bilateral ablation of the plantaris and gastrocnemius muscles and, after 7 days of recovery, were injected three times daily for 14 days with GH/IGF-I (1 mg/kg each; FO + GH/IGF-I group) or saline vehicle (FO group). Intact rats receiving saline vehicle served as controls (Con group). Muscle wet weight was 32% greater in the FO than in the Con group: 162 ± 8 vs. 123 ± 16 mg. Muscle weight in the FO + GH/IGF-I group (196 ± 14 mg) was 59 and 21% larger than in the Con and FO groups, respectively. Mean soleus fiber cross-sectional area of the FO + GH/IGF-I group (2,826 ± 445 μm2) was increased compared with the Con (2,044 ± 108 μm2) and FO (2,267 ± 301 μm2) groups. The difference in fiber size between the FO and Con groups was not significant. Mean myonuclear number increased in FO (187 ± 15 myonuclei/mm) and FO + GH/IGF-I (217 ± 23 myonuclei/mm) rats compared with Con (155 ± 12 myonuclei/mm) rats, although the difference between FO and FO + GH/IGF-I animals was not significant. The mean cytoplasmic volume per myonucleus (myonuclear domain) was similar across groups. These results demonstrate that the larger mean muscle weight and fiber cross-sectional area occurred when FO was combined with GH/IGF-I administration and that myonuclear number increased concomitantly with fiber volume. Thus there appears to be some mechanism(s) that maintains the myonuclear domain when a fiber hypertrophies.

scholarly journals A Comparison of the Arithmetic and Geometric Means in Estimating Stump Diameter, Basal Area, and Volume in Appalachian Hardwoods

2007 ◽  
Vol 24 (1) ◽  
pp. 71-73 ◽  
Author(s):  
Harry V. Wiant ◽  
John R. Brooks
Keyword(s):  
Geometric Mean ◽  
Basal Area ◽  
Cross Sectional Area ◽  
Practical Significance ◽  
Sectional Area ◽  
Cross Sectional ◽  
Geometric Means ◽  
The Difference ◽  
Appalachian Hardwoods ◽  
Stump Diameter

Abstract The difference between the use of the arithmetic and geometric means for estimation of average stump diameter, stump cross-sectional area and estimated tree volume was investigated using measurements from 739 stumps from an Appalachian hardwood stand located in central West Virginia. Although average stump diameter, cross-sectional area, and tree volumes were statistically different between estimates based on the arithmetic and geometric mean diameter, these differences were of little practical significance. The difference in average stem diameter, cross-sectional area, tree cubic volume, and board foot volume were 0.05 in, 0.01 ft2, 0.45 ft3, and 2.41 bd ft, respectively.

Intra- and inter-rater reliability in the cross-sectional area of feline lumbar epaxial musculature evaluated via abdominal CT scan

2019 ◽  
Vol 22 (8) ◽  
pp. 721-728
Author(s):  
Laura H Rayhel ◽  
Jessica M Quimby ◽  
Eric M Green ◽  
Valerie J Parker ◽  
Shasha Bai
Keyword(s):  
Ct Scan ◽  
Muscle Mass ◽  
Ct Images ◽  
Cross Sectional Area ◽  
Area Measurement ◽  
Thoracic Vertebrae ◽  
Sectional Area ◽  
Cross Sectional ◽  
Rater Reliability ◽  
Epaxial Muscle

Objectives The aim of this study was to evaluate the intra- and inter-rater reliability of epaxial muscle cross-sectional area measurement on feline CT images and to determine the relationship between normalized epaxial muscle area (EMA) and subjective muscle condition score (MCS). Methods Feline transverse CT images including the junction of the 13th thoracic vertebrae/13th rib head were retrospectively reviewed. Right and left epaxial muscle circumference and vertebral body height were measured and an average normalized EMA (ratio of epaxial area:vertebral height) was calculated for each image. Measurements were performed by three individuals blinded to the clinical data and were repeated 1 month later. Intra- and inter-rater reliability of EMA was assessed with concordance correlation coefficient (CCC), and Bland–Altman analysis was performed to assess bias and limits of agreement (LoA) between and within observers at different time points. In cats for which MCS data were available, EMA was compared between differing MCSs via the Kruskal–Wallis test, with Bonferroni-corrected Wilcoxon rank-sum post-hoc analysis. Results In total, 101 CT scans met the inclusion criteria for reliability analysis, 29 of which had muscle condition information available for analysis. Intra-rater EMA CCC ranged from 0.84 to 0.99 with minimal bias (range –0.16 to 0.08) and narrow LoA. Inter-rater EMA CCC ranged from 0.87 to 0.94, bias was larger (range –0.46 to 0.66) and LoA were wider when assessed between observers. Median EMA was significantly lower in cats with severe muscle atrophy (2.76, range 1.28–3.96) than in all other MCS groups ( P <0.0001 for all comparisons). Conclusions and relevance Measurement of EMA on CT showed strong intra-rater reliability, and median EMA measurements were significantly lower in cats with severe muscle wasting, as assessed on physical examination. Further studies correlating EMA to lean muscle mass in cats are needed to determine whether this method may be useful to quantify muscle mass in patients undergoing a CT scan.

Radiography and biomechanics of sixth and seventh cervical vertebrae segments after disc fenestration and after insertion of an intervertebral body spacer

2014 ◽  
Vol 27 (01) ◽  
pp. 54-61 ◽  
Author(s):  
L. Desquilbet ◽  
D. Fitzpatrick ◽  
F. Bernard ◽  
P. Moissonnier
Keyword(s):  
Intervertebral Disc ◽  
Cervical Vertebrae ◽  
Cross Sectional Area ◽  
Cervical Disc ◽  
Sectional Area ◽  
Lateral Bending ◽  
Disc Space ◽  
Cross Sectional ◽  
Radiographic Measurements ◽  
Flexion Extension

SummaryObjectives: To study the radiographic characteristics and the biomechanical properties of the sixth and seventh cervical (C6–C7) vertebral motion unit (VMU) with an intact disc, after disc fenestration, and after placement of an intervertebral body spacer (IVBS).Methods: Six cadaveric C6-C7 VMU were retrieved from six Greyhound cadavers. Each VMU was loaded at 3 Nm of torque sequentially in flexion, extension, and in right and left lateral bending. The range-of-motion (ROM) was measured with a Zebris 3D® system. The intervertebral disc cross-sectional area was measured on lateral and ventrodorsal radiographs. Biomechanical testing and radiographic measurements were performed with an intact disc, after disc fenestration, and after IVBS placement. Data were reported as mean ± SD.Results: The intervertebral disc cross-sectional area was significantly decreased after disc fenestration and increased after IVBS placement, but remained significantly smaller than the area of intact disc in some of the tested conditions. The ROM with an intact disc, after disc fenestration and after IVBS placement, in flexion were 11.5° ± 1.0, 15.2° ± 2.3, and 10.9° ± 4.7, respectively, and in extension were 15.6° ± 3.7, 24.7° ± 6.2, 21.9° ± 4.0, respectively. There was a significant increase in extension ROM after disc fenestration. Intervertebral body spacer placement significantly decreased ROM in flexion but ROM in extension was not different from disc fenestration. No significant changes in lateral bending ROM were detected.Clinical significance: The use of an IVBS reduced disc space collapse but did not restore stability of the VMU to normal values in extension after cervical disc fenestration.

Cross-sectional Area of Lumbar Vertebrae in Peri- and Postmenopausal Patients With and Without Osteoporosis

2000 ◽  
Vol 11 (4) ◽  
pp. 304-309 ◽  
Author(s):  
T. M. Link ◽  
M. Dören ◽  
G. Lewing ◽  
N. Meier ◽  
A. Heinecke ◽  
...  
Keyword(s):  
Lumbar Vertebrae ◽  
Cross Sectional Area ◽  
Sectional Area ◽  
Cross Sectional

scholarly journals On a method of determining the viscosity of gases, especially those available only in small quantities

1910 ◽  
Vol 83 (562) ◽  
pp. 265-276 ◽  
Keyword(s):  
Volume Content ◽  
Capillary Tube ◽  
Cross Sectional Area ◽  
The Other ◽  
Sectional Area ◽  
Cross Sectional ◽  
Fine Capillary ◽  
The Difference ◽  
Absolute Measurements ◽  
Unlimited Amount

The apparatus about to be described was designed for the purpose of comparing the viscosities of neon, xenon, and krypton—the loan of which Sir William Ramsay kindly offered the author—with that of air. With such small quantities of gas available, the volume content of the apparatus must obviously be correspondingly small, and therefore, it would seem, unsuitable for absolute measurements. The object of the present paper is to show that this is by no means the case. As will be seen later, the method is actually restricted to small quantities by the conditions of the experiments, but there is no reason why it should not be used even when the gas under test may be obtained in practically unlimited amount. Theory of the Method . Consider a closed glass vessel (as in fig. 1) consisting of two connected limbs, one a fine capillary tube and the other of much greater cross-sectional area, yet sufficiently narrow for a pellet of mercury to remain intact in it. Let V be the volume unoccupied by mercury (the volume of the capillary tube being considered negligible). Let P denote the steady pressure of the gas in the tube when the latter is held horizontally, and let p be the difference of pressure caused by the mercury pellet when the apparatus is vertical. Let p 1 be the pressure and v 1 the volume at any time above the mercury, and p 2 , v 2 , the corresponding quantities below the mercury. Then V = v 1 + v 2 , and p 2 - p 1 = p .

scholarly journals Correlation Analysis for the Selection of Microtitanium Plates with Different Specifications for use in a Cervical Vertebral Dome Expansion Laminoplasty

2020 ◽  
Author(s):  
Zhou Run-tian ◽  
Zhao Yi-bo ◽  
Lu Xiang-dong ◽  
Zhao Xiao-feng ◽  
Wang Xiao-nan ◽  
...  
Keyword(s):  
Spinal Cord ◽  
Correlation Analysis ◽  
Spinal Canal ◽  
Cervical Spinal Cord ◽  
Cervical Vertebrae ◽  
Cross Sectional Area ◽  
Sectional Area ◽  
Cross Sectional ◽  
Movement Distance ◽  
Selection Of

Abstract Backgrounds: Cervical vertebral dome expansion laminoplasty is a new surgical method for the treatment of cervical spondylosis. We analyzed correlations between the selection of microtitanium plates with different specifications for use in a cervical vertebral dome expansion laminoplasty to establish guidance for the selection of suitable microtitanium plates.Methods: Sixteen patients that underwent the new, full lamina posterior spinal canal enlargement with a cervical spinal stenosis angioplasty procedure for treatment of their cervical spinal cords were recruited at our hospital. From February 2017-September 2018, medical records confirmed that all patients underwent cervical CT and MRI tests pre- and postsurgery. The anteroposterior diameter of the spinal canal, changes in the cross-sectional area of the spinal canal, and the pre- and postsurgery distance of the cervical spinal cord after applying microtitanium plates with different lengths were measured by Mimics version 17.0 software. A statistical regression and correlation analysis of relevant specification parameters of the microtitanium plate was then studied.Results: As the size of the microtitanium plate increased, we found that the cross-sectional area of cervical spinal canal and distance between the descendants of the lamina and the distance of cervical spinal cord concordantly increased. The regression equation associated with sagittal diameter, cross-sectional area, and posterior movement distance of the cervical spinal cord was obtained.Conclusions: The use of the corresponding regression equations enabled the prediction of the cervical spinal canal parameters and posterior movement distance of the cervical spinal cord when adopting different specifications of the microtitanium plate for different segments of the cervical vertebrae. This analysis guided the selection of microtitanium plates with appropriate specifications for different cervical vertebrae in a cervical vertebral dome expansion laminoplasty.

scholarly journals The comparative study of analyzing the T-shaped and square-shaped concrete columns

2021 ◽  
Vol 331 ◽  
pp. 05005
Author(s):  
Ade Sri Wahyuni ◽  
Mukhlis Islam ◽  
Rizky Arian Putra
Keyword(s):  
Concrete Columns ◽  
Cross Sectional Area ◽  
Shape Effect ◽  
Strain Diagram ◽  
Sectional Area ◽  
Cross Sectional ◽  
Three Samples ◽  
The Difference ◽  
The Comparative Study ◽  
Calculation Analysis

This study aims to analyze how much changes in column shape effect have on the strength of the column structure. This calculation is comparing a square-shaped concrete column with two different axis of a T-shaped column. Each sample is compared in terms of 6 different column dimensions, however, the cross-sectional area within the three samples ( Square, T-shaped axis1 and 2) has remained constant. The concrete quality (fc') is kept at 30 MPa while the reinforcement area used 1% and 5%. Column calculation analysis is using Hognestad stress-strain diagram relationship and finite difference method. The result shows, the greater the reinforcement ratio, the greater the difference of Mn value and the smaller the difference of Pn value, of T-shaped and square column for each area. The same cross-sectional area does not necessarily lead to the same behavior of a T-shaped column with a different axis

scholarly journals (323) Alternate Approaches for Evaluating Horticultural Efficiency

HortScience ◽  
2005 ◽  
Vol 40 (4) ◽  
pp. 1038C-1038
Author(s):  
Timothy L. Righetti ◽  
Carmo Vasconcelos ◽  
David R. Sandrock ◽  
Samuel Ortega ◽  
Yerko Moreno
Keyword(s):  
Leaf Area ◽  
Cross Sectional Area ◽  
Sectional Area ◽  
Cross Sectional ◽  
Improvement Potential ◽  
Canopy Area ◽  
Alternate Assessments ◽  
Physiological Differences ◽  
The Difference ◽  
The Relationship

Four ratio-based efficiency expressions (yield/trunk cross-sectional area, yield/canopy area, yield/pruning weight, CO2 assimilation/leaf area) were evaluated. These expressions depend on the size of the denominator if the function describing the relationship between the denominator and the numerator has a non-zero intercept. When this occurs, it is difficult to determine if statistically different efficiency expressions reflect physiological differences or are caused by comparing expressions with different sized denominators. When denominators and numerators of efficiency expressions are plotted, the edge of the data cloud can often be statistically identified. The function describing the edge of the data cloud defines the maximum possible value (MPV) obtainable for a given value of the denominator. The percentage of MPV (%MPV) is an alternate efficiency expression that is not influenced by differing trunk cross-sectional area, canopy area, pruning weight, or leaf area. The difference between MPV and observed performance can be used to define improvement potential (IP). These alternate assessments can supplement traditional efficiency expressions. It is also possible to determine if statistical differences in traditional efficiency expressions are caused by differences in potential, differences in a plant or leaf's ability to achieve its potential, or differences in the size of the efficiency expression denominators.

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