scholarly journals Simulation of unsteady blood flow dynamics in the thoracic aorta

2017 ◽  
Vol 37 (3) ◽  
pp. 92-101 ◽  
Author(s):  
Santiago Laín ◽  
Andres D. Caballero

In this work, blood flow dynamics was analyzed in a realistic thoracic aorta (TA) model under unsteady-state conditions via velocity contours, secondary flow, pressure and wall shear stress (WSS) distributions. Our results demonstrated that the primary flow velocity is skewed towards the inner wall of the ascending aorta; but this skewness shifts towards the posterior wall in the aortic arch and then towards the anterior-outer wall in the descending aorta. Within the three arch branches, the flow velocity is skewed to the distal walls with flow reversal along the proximal walls. Strong secondary flow motion is observed in the TA, especially at the inlet of the arch branches. WSS is highly dynamic, but was found to be the lowest along the proximal walls of the arch branches. Finally, pressure was found to be low along the inner aortic wall and in the proximal walls of the arch branches, and high around the three stagnation regions distal to the arch branches and along the outer wall of the ascending aorta.

2011 ◽  
Vol 300 (2) ◽  
pp. F319-F329 ◽  
Author(s):  
Niels-Henrik Holstein-Rathlou ◽  
Olga V. Sosnovtseva ◽  
Alexey N. Pavlov ◽  
William A. Cupples ◽  
Charlotte Mehlin Sorensen ◽  
...  

Tubuloglomerular feedback (TGF) has an important role in autoregulation of renal blood flow and glomerular filtration rate (GFR). Because of the characteristics of signal transmission in the feedback loop, the TGF undergoes self-sustained oscillations in single-nephron blood flow, GFR, and tubular pressure and flow. Nephrons interact by exchanging electrical signals conducted electrotonically through cells of the vascular wall, leading to synchronization of the TGF-mediated oscillations. Experimental studies of these interactions have been limited to observations on two or at most three nephrons simultaneously. The interacting nephron fields are likely to be more extensive. We have turned to laser speckle contrast imaging to measure the blood flow dynamics of 50–100 nephrons simultaneously on the renal surface of anesthetized rats. We report the application of this method and describe analytic techniques for extracting the desired data and for examining them for evidence of nephron synchronization. Synchronized TGF oscillations were detected in pairs or triplets of nephrons. The amplitude and the frequency of the oscillations changed with time, as did the patterns of synchronization. Synchronization may take place among nephrons not immediately adjacent on the surface of the kidney.


2006 ◽  
Vol 38 (10) ◽  
pp. 1811-1818 ◽  
Author(s):  
MICHAEL E. TSCHAKOVSKY ◽  
NATASHA R. SAUNDERS ◽  
KATHERINE A. WEBB ◽  
DENIS E. O'DONNELL

1990 ◽  
Vol 8 (2) ◽  
pp. 167-172 ◽  
Author(s):  
Q. Guo ◽  
L. Friloux ◽  
O. Nalcioglu

The Analyst ◽  
2015 ◽  
Vol 140 (5) ◽  
pp. 1432-1437 ◽  
Author(s):  
Shantimoy Kar ◽  
Monika Dash ◽  
Tapas Kumar Maiti ◽  
Suman Chakraborty

We investigate blood flow dynamics on a rotationally actuated lab-on-a-compact disk (LOCD) platform, as a function of the hematocrit level of the blood sample.


1989 ◽  
Vol 246 (3) ◽  
pp. 147-150 ◽  
Author(s):  
M. Kawakami ◽  
K. Makimoto ◽  
T. Nakajima ◽  
H. Takahashi

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