Rheological and topographical factors affecting shear stress in the microcirculation

Herbert H. Lipowsky

Research output: Chapter in Book/Report/Conference proceedingConference contribution

1 Scopus citations

Abstract

Blood shear stresses (τwall) on the endothelium of the microvasculature have been shown to provide a stimulus for affecting endothelial metabolism and function, with ramifications which affect many physiological processes. Prevailing levels of τwall which generally equals the product of viscosity (η) and shear rate (γ), result from a complex interaction between network topography and the rheological properties of blood. To delineate those factors which affect this relationship, the distribution of blood flows (Q), γ, and microvascular hematocrits (Hmicro) were examined in parent and daughter branches of arteriolar and venular bifurcations in the intestinal mesentery by intravital microscopy. The results indicate that daughter to parent ratios of Q and γ, fall and rise, respectively, as daughter branch diameter (D) decreases relative to the parent vessel D. In contrast. Hmicro, the main determinant of η, remains relatively constant, suggesting that variations in η have a lesser influence on τwall at branch points. Analysis of flow apportionment at branch points in light of Murray's Law of optimum design,(Q-D1) suggests that network geometry alone does not adhere to this relationship, but that the resultant flow state gives rise to conditions which lessen variations of γ at branch points throughout the network.

Original languageEnglish (US)
Title of host publicationAdvances in Bioengineering
EditorsJohn M. Tarbell
PublisherPubl by ASME
Pages385-388
Number of pages4
ISBN (Print)0791810313
Publication statusPublished - Dec 1 1993
EventProceedings of the 1993 ASME Winter Annual Meeting - New Orleans, LA, USA
Duration: Nov 28 1993Dec 3 1993

Publication series

NameAmerican Society of Mechanical Engineers, Bioengineering Division (Publication) BED
Volume26

Other

OtherProceedings of the 1993 ASME Winter Annual Meeting
CityNew Orleans, LA, USA
Period11/28/9312/3/93

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All Science Journal Classification (ASJC) codes

  • Engineering(all)

Cite this

Lipowsky, H. H. (1993). Rheological and topographical factors affecting shear stress in the microcirculation. In J. M. Tarbell (Ed.), Advances in Bioengineering (pp. 385-388). (American Society of Mechanical Engineers, Bioengineering Division (Publication) BED; Vol. 26). Publ by ASME.