It is known that large arteries in situ are subjected to significant axial prestretch. This prestretch plays an important physiological role in optimizing the biomechanical response of an artery. It is also known that the prestretch declines with age. However, a detailed description of age-related changes in prestretch is available only for the abdominal aorta and for the femoropliteal artery. Our study presents results of measurements of axial prestretch in 229 left common carotid arteries excised in autopsies. It was found that the prestretch of the carotid artery correlates significantly with age ([Formula: see text], p value < 0.001). A linear regression model was used to fit the observations. Simultaneously with the measurement of the prestretch in the carotid artery, the axial prestretch was also measured in abdominal aorta. By comparing data obtained from these locations, it was concluded that the axial prestretch in the carotid artery is greater than in the abdominal aorta, and that atherosclerosis develops more rapidly in the abdominal aorta than in the carotid artery. Histological sections obtained from 8 carotid arteries and aortas suggest that the medial layer of the left common carotid artery is significantly thinner than aortic media (median/IQR: 0.343/0.086 vs. 0.482/0.172 mm, [Formula: see text] in Wilcoxon signed-rank test) and simultaneously that carotid media contains a lower number of elastic membranes (median/IQR: 26.5/11.8 vs. 31.5/11.8, [Formula: see text] in the Wilcoxon signed-rank test). This could be a reason for the different extent of the prestretch observed in aorta and in carotid artery. Our data sample also contains 5 measurements of the axial prestretch in abdominal aortas suffering from an aneurysm. It was found that aneurysmatic aortas also exhibit axial retraction when excised from in situ position. To the best of our knowledge, this is the first time that detailed data characterizing axial prestretch of the human left common carotid artery have been presented.
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http://dx.doi.org/10.1007/s10237-016-0797-y | DOI Listing |
Comput Methods Programs Biomed
December 2024
Department of Mechanics, Kunming University of Science and Technology, Kunming 650500, PR China.. Electronic address:
Background And Objective: It is an indisputable physiological phenomenon that the arterial axial pre-stretch ratio (AAPSR) decreases with age, but little attention has been paid to the effect of this reduction on chronic diseases during aging.
Methods: Here we reported an experimental method to simulate arteries aging, developed a fluid-structure interaction model with the effect of AAPSR changes, and compared it with the anatomy data and structural parameters of the human thoracic aorta.
Results: We showed that with the process of aging, the decrease of AAPSR leads to a decline of arterial elasticity, a decrease of arterial elastic strain energy, which weakens the ability to promote blood circulation, the corresponding decrease in cardiac output (CO) and cerebral blood flow (CBF) causes distal organ and body tissue ischemia, which is one of the main causes of increased blood pressure and decreased cerebral perfusion in the elderly.
Clin Biomech (Bristol)
December 2024
Department of Anatomy and Physiology, Faculty of Medicine, Saga University, 5-1-1 Nabeshima, Saga 849-8501, Japan.
Polymers (Basel)
October 2022
State Key Laboratory of New Textile Materials and Advanced Processing Technologies, Wuhan Textile University, Wuhan 430200, China.
Thermal residual strains/stresses cause several defects in hybrid structures and various studies have reported the reduction of residual strain. This paper describes a method for reducing thermal residual strains/stresses in metal-CFRP-metal hybrid tubes (MCMHT). The proposed axial preload tool provides two ways to reduce the thermal residual strains/stresses during the co-cure bonding process: pre-compressing of the metal layers and pre-stretching of the unidirectional carbon fiber reinforced polymer (CFRP) layers.
View Article and Find Full Text PDFComput Biol Med
April 2022
Institute of Solid Mechanics, Mechatronics and Biomechanics (ISMMB), Faculty of Mechanical Engineering (FME), Brno University of Technology (BUT), Technicka 2896/2, 61669, Brno, Czech Republic.
Introduction: Computational modeling can enhance the understanding of cell mechanics. To achieve this, finite element models of endothelial cells were proposed with shapes mimicking their natural state inside the endothelium within the cardiovascular system. Implementing the recently proposed bendo-tensegrity concept, these models consider flexural (buckling) as well as tensional/compressional behavior of microtubules and also incorporate the waviness of intermediate filaments.
View Article and Find Full Text PDFJ Biomech
February 2022
Applied Mechanics and Bioengineering, Aragón Institute of Engineering Research (I3A), University of Zaragoza, Spain; Department of Mechanical Engineering, University of Zaragoza, Spain; CIBER de Bioingeniería, Biomateriales y Nanomedicina (CIBER-BBN), Zaragoza, Spain. Electronic address:
We analyze the residual stresses and mechanical properties of layer-dissected infrarenal abdominal aorta (IAA). We measured the axial pre-stretch and opening angle and performed uniaxial tests to study and compare the mechanical behavior of both intact and layer-dissected porcine IAA samples under physiological loads. Finally, some of the most popular anisotropic hyperelastic constitutive models (GOH and microfiber models) were proposed to estimate the mechanical properties of the abdominal aorta by least-square fitting of the recorded in-vitro uniaxial test results.
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