Biomechanics of microcirculatory blood perfusion

The microcirculation represents a region of the circulation in which blood vessels are directly surrounded by the tissue and cells to which they suppl y nutrients and from which they collect metabolites. The cellular elements that make up the microcirculation have now been identified, and a large bod y of evidence has become available that provides molecular definitions of t hese elements. The blood flow is in a domain in which viscous stresses domi nate, but the viscoelastic and active properties of cells lead to nonlinear problems. The ability of cells to actively control cytoplasmic mechanical properties and shape, as well as their membrane adhesion, leads to unique c ell behavior in microvessels that has a direct influence on organ transport and function. There is also increasing evidence that the properties of the cells are in turn influenced by fluid shear stresses. These issues have gr eatly expanded the scope of microvascular analysis. The microcirculation is one of the sites in which diseases manifest themselves at an early stage. The application of biomechanical analysis of the microcirculation is starti ng to focus on diseases. The field is rich with problems of high significan ce.