Related Experiment Video
Updated: Jul 24, 2026

Non-invasive Assessment of Microvascular and Endothelial Function
Published on: January 29, 2013
[Changes of blood flow structure in precapillary microvessels during significant slow-down of flow]
Abstract:
The experiments were carried out with a special "biological model" in which the rabbits' red blood cell suspension possessing low hematocrit circulated in frogs' mesenterial microvessels. Red blood cell behaviour was investigated in microvessels of 19-45 microns in diameter under conditions of arbitrarily changed flow velocity in mesenterial microvessels. Automatic frame-to-frame analysis of cinematographic films with the texture analysis system (Ernst Leitz, FRG) showed that the velocity fluctuations of individual red blood cells and their radial displacements increased significantly, while their velocity profile became blunt, during slowing-down of flow from 0.7 to 0.2 mm/s. Thus the normal blood flow structure in microvessels becomes disordered under ischemic conditions entailing disturbance of blood rheological properties and creating additionally increased resistance in the vessels.
Related Concept Videos
Blood Flow
Structure of Blood Vessels
Capillary Beds
Capillaries connect arterioles, small branches of arteries, to venules,...
Venules
Venules are much smaller in diameter compared to their larger counterparts, the veins. They are generally 8 to 100 micrometers in diameter, significantly smaller than the size of veins. The walls of venules are thin, consisting of the endothelium, a thin layer of connective tissue, and occasionally a few smooth muscle cells. This structural simplicity is a stark contrast...
Autoregulation of Blood Flow
Chemical Signaling in Autoregulation
Chemical signaling operates at the precapillary sphincter level, inciting either contraction or relaxation.

