Document Detail


The dispersion of indicator flowing through simplified models of the circulation and its relevance to velocity profile in blood vessels.
MedLine Citation:
PMID:  5918057     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
1. The distribution of velocity (velocity profile) was studied in water flowing through simple models of the circulation. Dye was injected and the distribution of velocity was assessed from indicator concentration-time curves recorded with a photomultiplier.2. Observations were made on straight and curved tubes and on a tube containing a short region with an elliptical cross-section. With steady flow, the rate was varied over the range 24-870 ml./min (Reynolds number 102-3690). Sinusoidal pulsations were imposed on the steady flow in some experiments.3. Bends gave rise to large secondary flows. These caused mixing across the flow and a marked reduction in the variation of velocity over the cross-section of the tube. The effect of bends on velocity distribution was maximal at a Reynolds number of ca. 1000. Similar, but far smaller, effects were seen in a region with an elliptical cross-section and when the flow was made pulsatile. Secondary motion due to bends was capable of preventing a heavier-than-water indicator (sp.gr. 1.375) from settling out of the flow.4. The experimental findings suggest that there may be secondary flows in vascular beds. Under certain conditions, these would prevent the establishment of Poiseuille type laminar flow. The possible physiological importance of the findings is discussed.
Authors:
C G Caro
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Publication Detail:
Type:  Journal Article    
Journal Detail:
Title:  The Journal of physiology     Volume:  185     ISSN:  0022-3751     ISO Abbreviation:  J. Physiol. (Lond.)     Publication Date:  1966 Aug 
Date Detail:
Created Date:  1966-12-26     Completed Date:  1966-12-26     Revised Date:  2009-11-18    
Medline Journal Info:
Nlm Unique ID:  0266262     Medline TA:  J Physiol     Country:  ENGLAND    
Other Details:
Languages:  eng     Pagination:  501-19     Citation Subset:  IM    
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MeSH Terms
Descriptor/Qualifier:
Blood Circulation / physiology*
Blood Flow Velocity*
Coloring Agents / analysis
Models, Theoretical
Water
Chemical
Reg. No./Substance:
0/Coloring Agents; 7732-18-5/Water
Comments/Corrections

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