Tracheal dimensions at full inflation and deflation in adolescent twins

1991 ◽  
Vol 70 (4) ◽  
pp. 1781-1786 ◽  
Author(s):  
Y. Kawakami ◽  
M. Nishimura ◽  
H. Kusaka
Keyword(s):  
Genetic Factors ◽  
Total Lung Capacity ◽  
Cross Sectional Area ◽  
Residual Volume ◽  
Sectional Area ◽  
Male Adolescent ◽  
Cross Sectional ◽  
Lung Capacity ◽  
Genetic Components ◽  
Adolescent Twins

Tracheal dimensions at total lung capacity (TLC) and residual volume (RV) were analyzed roentgenographically in 17 pairs of male adolescent twins (mean age 16.3 yr; 12 monozygotic pairs and 5 dizygotic pairs). Genetic factors dominated environmental traits in intra- as well as extrathoracic tracheal width at RV. Extrathoracic tracheal width at TLC was also governed by genetic components. Intrathoracic tracheal depth (anteroposterior diameter), length, and cross-sectional area did not seem to be genetically controlled at TLC and RV. Intrathoracic tracheal cross-sectional area increased by 14.4% and became more elliptical from RV to TLC, owing mainly to an increase in tracheal depth (16.7%). Increments from RV to TLC in tracheal depth but not width correlated with increases in lung width, depth, and height. Intrathoracic trachea was elongated 14% in association with increase in lung height from RV to TLC. At TLC, extrathoracic tracheal width was larger than intrathoracic tracheal width, but this dimension did not differ at RV. These results indicate that genetic factors influence, at least at RV, the tracheal rings more strongly than membranous parts. Intrathoracic tracheal depth but not width increases during inspiration in accordance with increase in lung volume. Extrathoracic tracheal width widens more than intrathoracic trachea from RV to TLC.

Diaphragmatic displacement measured by fluoroscopy and derived by Respitrace

1989 ◽  
Vol 67 (2) ◽  
pp. 694-698 ◽  
Author(s):  
J. A. Verschakelen ◽  
K. Deschepper ◽  
T. X. Jiang ◽  
M. Demedts
Keyword(s):  
Total Lung Capacity ◽  
Anterior Part ◽  
Posterior Part ◽  
Middle Part ◽  
Cross Sectional Area ◽  
Sectional Area ◽  
Cross Sectional ◽  
Lung Volumes ◽  
Lung Capacity ◽  
Diaphragmatic Motion

In eight healthy volunteers we simultaneously measured the axial diaphragmatic motion by fluoroscopy and the cross-sectional area changes of the rib cage (RC) and abdomen (ABD) by Respitrace (RIP) during semistatic vital capacities (VC). We found that, if the fluoroscopic axial displacement of the posterior part of the diaphragm between residual volume (RV) and total lung capacity (TLC) is considered equal to 100%, the movement of the middle part is 90%, whereas that of the anterior part is only approximately 60%; the ratio of the axial displacements to mouth volume, furthermore, decreases at high lung volumes, especially for the anterior part. The RIP signal is nearly linearly related to mouth volume, but the contribution of the RC (delta RC) progressively increases (and is approximately 80% RIP at TLC), whereas the volume contribution of the ABD (delta ABD) levels off (to 20% RIP at TLC). The diaphragmatic volume displacement calculated from the theoretical analysis described by Mead and Loring also levels off at high volumes similarly as the ABD but is approximately 50% RIP at TLC. Finally, the axial movements of the three parts of the diaphragm are linearly related to the RC and ABD cross-sectional-area changes (r 0.91–0.97) and are even significantly better correlated with the “calculated” diaphragmatic volume displacement.

scholarly journals Functional effect of longitudinal heterogeneity in constricted airways before and after lung expansion

2012 ◽  
Vol 112 (1) ◽  
pp. 237-245 ◽  
Author(s):  
C. Wongviriyawong ◽  
R. S. Harris ◽  
H. Zheng ◽  
M. Kone ◽  
T. Winkler ◽  
...  
Keyword(s):  
Lung Volume ◽  
Total Lung Capacity ◽  
Cross Sectional Area ◽  
Cylindrical Shape ◽  
Sectional Area ◽  
High Resolution Computed Tomography ◽  
Cross Sectional ◽  
Lung Capacity ◽  
Lung Expansion ◽  
Before And After

Heterogeneity in narrowing among individual airways is an important contributor to airway hyperresponsiveness. This paper investigates the contribution of longitudinal heterogeneity (the variability along the airway in cross-sectional area and shape) to airway resistance ( Raw). We analyzed chest high-resolution computed tomography scans of 8 asthmatic (AS) and 9 nonasthmatic (NA) subjects before and after methacholine (MCh) challenge, and after lung expansion to total lung capacity. In each subject, Raw was calculated for 35 defined central airways with >2 mm diameter. Ignoring the area variability and noncircular shape results in an underestimation of Raw (%Utotal) that was substantial in some airways (∼50%) but generally small (median <6%). The average contribution of the underestimation of Raw caused by longitudinal heterogeneity in the area (%Uarea) to %Utotal was 36%, while the rest was due to the noncircularity of the shape (%Ushape). After MCh challenge, %Uarea increased in AS and NA ( P < 0.05). A lung volume increase to TLC reduced %Utotal and %Uarea in both AS and NA ( P < 0.0001, except for %Utotal in AS with P < 0.01). Only in NA, %Ushape had a significant reduction after increasing lung volume to TLC ( P < 0.005). %Uarea was highly correlated, but not identical to the mean-normalized longitudinal heterogeneity in the cross-sectional area [CV2( A)] and %Ushape to the average eccentricity of the elliptical shape. This study demonstrates that Raw calculated assuming a cylindrical shape and derived from an average area along its length may, in some airways, substantially underestimate Raw. The observed changes in underestimations of Raw with the increase in lung volume to total lung capacity may be consistent with, and contribute in part to, the differences in effects of deep inhalations in airway function between AS and NA subjects.

Capillary and fiber geometry in rat diaphragm perfusion fixed in situ at different sarcomere lengths

1992 ◽  
Vol 73 (1) ◽  
pp. 151-159 ◽  
Author(s):  
D. C. Poole ◽  
O. Mathieu-Costello
Keyword(s):  
Airway Pressure ◽  
Sarcomere Length ◽  
Total Lung Capacity ◽  
Potential Range ◽  
Residual Volume ◽  
Capillary Length ◽  
Fiber Volume ◽  
Cross Sectional ◽  
Lung Capacity

To determine the potential range of diaphragm sarcomere lengths in situ and the effect of changes in sarcomere length on capillary and fiber geometry, rat diaphragms were perfusion fixed in situ with glutaraldehyde at different airway pressures and during electrical stimulation. The lengths of thick (1.517 +/- 0.007 microns) and thin (1.194 +/- 0.048 microns) filaments were not different from those established for rat limb muscle. Morphometric techniques were used to determine fiber cross-sectional area, sarcomere length, capillary orientation, and capillary length and surface area per fiber volume. All measurements were referenced to sarcomere length, which averaged 2.88 +/- 0.08 microns at -20 to -25 cmH2O airway pressure (residual volume) and 2.32 +/- 0.05 microns at +20 to +26 cmH2O airway pressure (total lung capacity). The contribution of capillary tortuosity and branching to total capillary length was dependent on sarcomere length and varied from 5 to 22%, consistent with that shown previously for mammalian limb muscles over this range of sarcomere lengths. Capillary length per fiber volume [Jv(c,f)] was significantly greater at residual volume (3,761 +/- 193 mm-2) than at total lung capacity (3,142 +/- 118 mm-2) and correlated with sarcomere length [l; r = 0.628, Jv(c,f) = 876l + 1,156, P less than 0.01; n = 18]. We conclude that the diaphragm is unusual in that the apparent in situ minimal sarcomere length is greater than 2.0 microns.(ABSTRACT TRUNCATED AT 250 WORDS)

scholarly journals Genetic and environmental influences on skeletal muscle phenotypes as a function of age and sex in large, multigenerational families of African heritage

2007 ◽  
Vol 103 (4) ◽  
pp. 1121-1127 ◽  
Author(s):  
Steven J. Prior ◽  
Stephen M. Roth ◽  
Xiaojing Wang ◽  
Candace Kammerer ◽  
Iva Miljkovic-Gacic ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Lean Mass ◽  
Genetic Correlations ◽  
Cross Sectional Area ◽  
Calf Muscle ◽  
Sectional Area ◽  
Cross Sectional ◽  
African Heritage ◽  
Genetic Components ◽  
Muscle Cross Sectional Area

The aim of this study was to estimate the heritability of and environmental contributions to skeletal muscle phenotypes (appendicular lean mass and calf muscle cross-sectional area) in subjects of African descent and to determine whether heritability estimates are impacted by sex or age. Body composition was measured by dual-energy X-ray absorptiometry and computed tomography in 444 men and women aged 18 yr and older (mean: 43 yr) from eight large, multigenerational Afro-Caribbean families (family size range: 21–112). Using quantitative genetic methods, we estimated heritability and the association of anthropometric, lifestyle, and medical variables with skeletal muscle phenotypes. In the overall group, we estimated the heritability of lean mass and calf muscle cross-sectional area (h2 = 0.18–0.23, P < 0.01) and contribution of environmental factors to these phenotypes ( r2 = 0.27–0.55, P < 0.05). In our age-specific analysis, the heritability of leg lean mass was lower in older vs. younger individuals (h2 = 0.05 vs. 0.23, respectively, P = 0.1). Sex was a significant covariate in our models ( P < 0.001), although sex-specific differences in heritability varied depending on the lean mass phenotype analyzed. High genetic correlations (ρG = 0.69–0.81; P < 0.01) between different lean mass measures suggest these traits share a large proportion of genetic components. Our results demonstrate the heritability of skeletal muscle traits in individuals of African heritage and that heritability may differ as a function of sex and age. As the loss of skeletal muscle mass is related to metabolic abnormalities, disability, and mortality in older individuals, further research is warranted to identify specific genetic loci that contribute to these traits in general and in a sex- and age-specific manner.

scholarly journals Volume displaced by diaphragm motion in emphysema

2001 ◽  
Vol 91 (5) ◽  
pp. 1913-1923 ◽  
Author(s):  
Bhajan Singh ◽  
Peter R. Eastwood ◽  
Kevin E. Finucane
Keyword(s):  
Functional Residual Capacity ◽  
Vital Capacity ◽  
Cross Sectional Area ◽  
X Rays ◽  
Sectional Area ◽  
Cross Sectional ◽  
Lung Capacity ◽  
Residual Capacity ◽  
Lateral Chest ◽  
Diaphragm Motion

To examine the effect of hyperinflation on the volume displaced by diaphragm motion (ΔVdi), we compared nine subjects with emphysema and severe hyperinflation [residual volume (RV)/total lung capacity (TLC) 0.65 ± 0.08; mean ± SD] with 10 healthy controls. Posteroanterior and lateral chest X rays at RV, functional residual capacity, one-half inspiratory capacity, and TLC were used to measure the length of diaphragm apposed to ribcage (Lap), cross-sectional area of the pulmonary ribcage, ΔVdi, and volume beneath the lung-apposed dome of the diaphragm. Emphysema subjects, relative to controls, had increased Lap at comparable lung volumes (4.3 vs. 1.0 cm near predicted TLC, 95% confidence interval 3.4–5.2 vs. 0–2.1), pulmonary rib cage cross-sectional area (emphysema/controls 1.22 ± 0.03, P < 0.001 at functional residual capacity), and ΔVdi/ΔLap (0.25 vs. 0.14 liters/cm, P < 0.05). During a vital capacity inspiration, relative to controls, ΔVdi was normal in five (1.94 ± 0.51 liters) and decreased in four (0.51 ± 0.40 liters) emphysema subjects, and volume beneath the dome did not increase in emphysema (0 ± 0.36 vs. 0.82 ± 0.80 liters, P < 0.05). We conclude that ΔVdi can be normal in emphysema because 1) hyperinflation is shared between ribcage and diaphragm, preserving Lap, and 2) the diaphragm remains flat during inspiration.

Sex differences in growth patterns of the airways and lung parenchyma in children

1984 ◽  
Vol 56 (5) ◽  
pp. 1204-1210 ◽  
Author(s):  
R. D. Pagtakhan ◽  
J. C. Bjelland ◽  
L. I. Landau ◽  
G. Loughlin ◽  
W. Kaltenborn ◽  
...  
Keyword(s):  
Sex Differences ◽  
Vital Capacity ◽  
Total Lung Capacity ◽  
Somatic Growth ◽  
Lung Parenchyma ◽  
Growth Patterns ◽  
Sectional Area ◽  
Cross Sectional ◽  
Lung Capacity ◽  
Rates Of Growth

Seventeen boys and 19 girls, 8–15 yr in age, were studied to ascertain, in the two sex groups, the predictors of airway size [assessed by measurement of tracheal cross-sectional area (CSA) and maximal expiratory flows (Vmax)] and the relative rates of growth of the major divisions of the airways and lung parenchyma. In boys, total lung capacity (TLC) accounted for 77% of the variance of CSA and for 66% of the variability of Vmax. In contrast, somatic growth and maturation in girls accounted for only 45% of the variance of CSA and for 64% of the variability of Vmax; TLC was relatively unimportant. In boys, but not in girls, TLC-corrected CSA was significantly and inversely related to height and to TLC. In girls, TLC-corrected Vmax at 50 and 75% of forced vital capacity were directly related to height. These observations suggest different patterns of airway-parenchymal-somatic growth relationships in the two sexes. Furthermore, parenchymal growth appears to be the best determinant of airway growth in boys. In girls, other factors, perhaps genetic in nature, besides growth of parenchyma, may help determine airway size.

Effects of acute hyperinflation on chest wall mechanics in dogs

1987 ◽  
Vol 63 (4) ◽  
pp. 1493-1498 ◽  
Author(s):  
M. Decramer ◽  
T. X. Jiang ◽  
M. Demedts
Keyword(s):  
Tidal Volume ◽  
Chest Wall ◽  
Total Lung Capacity ◽  
Emg Activity ◽  
Sectional Area ◽  
Cross Sectional ◽  
Lung Capacity ◽  
Chest Wall Mechanics ◽  
Gastric Pressure ◽  
Residual Capacity

We studied chest wall mechanics at functional residual capacity (FRC) and near total lung capacity (TLC) in 14 supine anesthetized and vagotomized dogs. During breathing near TLC compared with FRC, tidal volume decreased (674 +/- 542 vs. 68 +/- 83 ml; P less than 0.025). Both inspiratory changes in gastric pressure (4.5 +/- 2.5 vs. -0.2 +/- 2.0 cmH2O; P less than 0.005) and changes in abdominal cross-sectional area (25 +/- 17 vs. -1.0 +/- 4.2%; P less than 0.001) markedly decreased; they were both often negative during inspiration near TLC. Parasternal intercostal shortening decreased (-3.0 +/- 3.7 vs. -2.0 +/- 2.7%), whereas diaphragmatic shortening decreased slightly more in both costal and crural parts (costal -8.4 +/- 2.9 vs. -4.3 +/- 4.1%, crural -22.8 +/- 13.2 vs. -10.0 +/- 7.5%; P less than 0.05). As a result, the ratio of parasternal to diaphragm shortening increased near TLC (0.176 +/- 0.135 vs. 0.396 +/- 0.340; P less than 0.05). Electromyographic (EMG) activity in the parasternals slightly decreased near TLC, whereas the EMG activity in the costal and crural parts of the diaphragm slightly increased. We conclude that 1) the mechanical outcome of diaphragmatic contraction near TLC is markedly reduced, and 2) the mechanical outcome of parasternal intercostal contraction near TLC is clearly less affected.

Pelvic Canal Narrowing Caused by Triple Pelvic Osteotomy in the Dog

1994 ◽  
Vol 07 (03) ◽  
pp. 110-113 ◽  
Author(s):  
D. L. Holmberg ◽  
M. B. Hurtig ◽  
H. R. Sukhiani
Keyword(s):  
Postoperative Complications ◽  
Pelvic Osteotomy ◽  
Cross Sectional Area ◽  
Sectional Area ◽  
Cross Sectional ◽  
Canal Width ◽  
Operative Complications ◽  
Post Operative Complications

SummaryDuring a triple pelvic osteotomy, rotation of the free acetabular segment causes the pubic remnant on the acetabulum to rotate into the pelvic canal. The resulting narrowing may cause complications by impingement on the organs within the pelvic canal. Triple pelvic osteotomies were performed on ten cadaver pelves with pubic remnants equal to 0, 25, and 50% of the hemi-pubic length and angles of acetabular rotation of 20, 30, and 40 degrees. All combinations of pubic remnant lengths and angles of acetabular rotation caused a significant reduction in pelvic canal-width and cross-sectional area, when compared to the inact pelvis. Zero, 25, and 50% pubic remnants result in 15, 35, and 50% reductions in pelvic canal width respectively. Overrotation of the acetabulum should be avoided and the pubic remnant on the acetabular segment should be minimized to reduce postoperative complications due to pelvic canal narrowing.When performing triple pelvic osteotomies, the length of the pubic remnant on the acetabular segment and the angle of acetabular rotation both significantly narrow the pelvic canal. To reduce post-operative complications, due to narrowing of the pelvic canal, overrotation of the acetabulum should be avoided and the length of the pubic remnant should be minimized.

DETERMINATION OF THE FUNCTION OF THE ROD’S CROSS-SECTIONAL AREA USING VIBRATION EIGENFREQUENCIES

2020 ◽  
Vol 0 (4) ◽  
pp. 19-24
Author(s):  
I.M. UTYASHEV ◽  
◽  
A.A. AITBAEVA ◽  
A.A. YULMUKHAMETOV ◽  
◽  
...  
Keyword(s):  
Cross Sectional Area ◽  
Variable Cross ◽  
Sectional Area ◽  
Longitudinal Vibrations ◽  
Cross Sectional ◽  
Method Error ◽  
Various Boundary Conditions ◽  
Elastic Fixation ◽  
Crosssectional Area

The paper presents solutions to the direct and inverse problems on longitudinal vibrations of a rod with a variable cross-sectional area. The law of variation of the cross-sectional area is modeled as an exponential function of a polynomial of degree n . The method for reconstructing this function is based on representing the fundamental system of solutions of the direct problem in the form of a Maclaurin series in the variables x and λ. Examples of solutions for various section functions and various boundary conditions are given. It is shown that to recover n unknown coefficients of a polynomial, n eigenvalues are required, and the solution is dual. An unambiguous solution was obtained only for the case of elastic fixation at one of the rod’s ends. The numerical estimation of the method error was made using input data noise. It is shown that the error in finding the variable crosssectional area is less than 1% with the error in the eigenvalues of longitudinal vibrations not exceeding 0.0001.

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