Interrelationship between Arteriolar Blood Flow Distribution and Capillary Perfusion in Skeletal Muscle

2015 ◽  
pp. 84-92 ◽  
Author(s):  
L. Lindbom ◽  
K. -E. Arfors
Keyword(s):  
Skeletal Muscle ◽  
Blood Flow ◽  
Flow Distribution ◽  
Blood Flow Distribution ◽  
Capillary Perfusion

Reduced exercise capacity in senescent beagles: an evaluation of the periphery

1991 ◽  
Vol 260 (1) ◽  
pp. H173-H182 ◽  
Author(s):  
G. C. Haidet ◽  
D. Parsons
Keyword(s):  
Skeletal Muscle ◽  
Blood Flow ◽  
Exercise Capacity ◽  
Maximal Exercise ◽  
Flow Distribution ◽  
Capillary Density ◽  
Blood Flow Distribution ◽  
Arterial Blood ◽  
Age Related ◽  
Age Related Changes

This study investigated the effect of age on peripheral factors involved in the systemic response to maximal exercise. Skeletal muscle was analyzed and regional blood flow distribution was determined at rest and during maximal exercise in senescent (old) and in younger mature (young) beagles. Maximal exercise capacity was significantly reduced (P less than 0.05) in old and was associated with a reduction in cardiac output (CO), as well as a tendency for arteriovenous O2 difference to be reduced, with a concomitant reduction in maximal O2 consumption. In each regional circulation evaluated, resting blood flow was similar in young and old. During exercise, blood flow was similar in young and old to the diaphragm, heart, tongue, and six of seven locomotory muscles. Concomitant blood flow reductions in splanchnic regions tended to be more pronounced in old than in young. Skeletal muscle analyses of triceps, semitendinosus, and gastrocnemius muscles disclosed similar percent fiber type distribution in young and old but a reduction in type II fiber area in old. In addition, both muscle capillary density and capillary-to-fiber ratio were reduced in old. These results demonstrate that age-related changes in blood flow distribution during maximal exercise enable skeletal muscle blood flow to be maintained in old, despite reductions in maximal CO and in muscle capillary density. However, this pattern of blood flow distribution only partially compensates for the combined effects of age-related changes in metabolic potential of the periphery, O2 content of arterial blood, and cardiac function during maximal exercise in old.

Fractals describe blood flow heterogeneity within skeletal muscle and within myocardium

1995 ◽  
Vol 268 (1) ◽  
pp. H112-H116 ◽  
Author(s):  
P. O. Iversen ◽  
G. Nicolaysen
Keyword(s):  
Skeletal Muscle ◽  
Blood Flow ◽  
Good Description ◽  
Regional Blood Flow ◽  
Flow Distribution ◽  
Left Ventricular ◽  
Relative Dispersion ◽  
Blood Flow Distribution ◽  
Fractal Analyses ◽  
D Values

A marked perfusion heterogeneity exists within single skeletal muscles and within the left ventricular (LV) myocardium. The relative dispersion (RD) of blood flows to regions < 1 g amounts to approximately 0.35 in both organs in rabbits. RD is changed with refinement of spatial resolution because the observed variance in regional flows increases. It has been shown with fractal analyses that the fractal dimension (D) can describe the relationship between the measured RD and size of the region studied within both the myocardium and the lung. A similar study has not been done with skeletal muscle. Barbital-anesthetized rabbits, cats, and sheep were used. Regional blood flow distribution was assessed with the microsphere method. Microsphere deposition in organ regions was determined after successive regrouping of either the LV or one skeletal muscle into various sized regions. We found that the perfusion patterns could be described with fractals for both organs, with the corresponding D values of 1.22-1.37 for the myocardium and 1.30-1.46 for muscle. It appears that fractals also yield a good description of blood flow distribution within skeletal muscle. In rabbits, D for myocardium was strongly correlated to the D for muscle (correlation coefficient = 0.98). This surprising finding of the strong correlation in D sampled from two organs originating from the same rabbit has hitherto not been reported.

Numerical Analysis of the VAD Outflow Cannula Positioning on the Blood Flow in the Patient–Specific Brain Supplying Arteries

2020 ◽  
Vol 22 (2) ◽  
pp. 619-636 ◽  
Author(s):  
Zbigniew Tyfa ◽  
Damian Obidowski ◽  
Krzysztof Jóźwik
Keyword(s):  
Blood Flow ◽  
Computer Aided Design ◽  
Volume Flow Rate ◽  
Flow Distribution ◽  
Primary Objective ◽  
Patient Specific ◽  
Blood Flow Distribution ◽  
Reconstruction Process ◽  
Outflow Cannula ◽  
The Brain

AbstractThe primary objective of this research can be divided into two separate aspects. The first one was to verify whether own software can be treated as a viable source of data for the Computer Aided Design (CAD) modelling and Computational Fluid Dynamics CFD analysis. The second aspect was to analyze the influence of the Ventricle Assist Device (VAD) outflow cannula positioning on the blood flow distribution in the brain-supplying arteries. Patient-specific model was reconstructed basing on the DICOM image sets obtained with the angiographic Computed Tomography. The reconstruction process was performed in the custom-created software, whereas the outflow cannulas were added in the SolidWorks software. Volumetric meshes were generated in the Ansys Mesher module. The transient boundary conditions enabled simulating several full cardiac cycles. Performed investigations focused mainly on volume flow rate, shear stress and velocity distribution. It was proven that custom-created software enhances the processes of the anatomical objects reconstruction. Developed geometrical files are compatible with CAD and CFD software – they can be easily manipulated and modified. Concerning the numerical simulations, several cases with varied positioning of the VAD outflow cannula were analyzed. Obtained results revealed that the location of the VAD outflow cannula has a slight impact on the blood flow distribution among the brain supplying arteries.

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