Speaker
Chaouqi Misbah
(Laboratoire Interdisciplinaire de Physique, Univ. J. Fourier and CNRS)
Description
Red blood cells (RBCs) dictate Blood flow properties, in
healthy conditions. Intricate collective phenomena will be
described. It will be shown that blood flow elements, if
hematocrit is not too large, organize in ordered patterns
with several impacts on rheology. Simulation results
together with experimental observations will be reported.
For example, spatial organization significantly lower the
effective viscosity, and limits the increase of the
viscosity with hematocrit in microcirculation, ensuring a
proper regulation of oxygen transport even when hematocrit
is sensibly beyond the normally admitted value. For example,
athletics adopting blood doping as well as in some diseases
(like primary and secondary polycythemia) an increase in
hematocrit normally causes blood to become more viscous in
macrocirculation. However, in microcirculation, depletion of
RBCs close to the vessel walls, as well as spatial
organization significantly moderate the increase of
viscosity with hematocrit.
