In vivo and in silico red blood cell lingering and partitioning in the microcirculation*

Erythrocytes, also known as red blood cells, are the most abundant type of cells in the human body. Among the mechanical peculiarities of these cells are their specific shape and high flexibility. These properties are known to be critical for the cells to travel in the capillaries of our circulatory system, whose cross section is sometimes smaller than the erythrocytes diameter. It has also been shown recently that their flexibility can lead them to linger at bifurcations of the microcirculatory system. In this presentation, we discuss how to quantify the amplitude of this lingering. We applied this quantification to both in vivo measurements in the microcirculatory system of hamster and to numerical simulations. This reveals that the lingering competes with the classical Zweifach-Fung effect, which governs their partitioning through bifurcations of bigger vessels. More accurately, we demonstrate a linear correlation between the lingering amplitude and deviations from the classical model of erythrocytes partitioning from the literature. This opens new interpretation to the hinderance of microcirculation by rigidified erythrocytes.