Best-law At the microscopic scale, the effects of individual red blood cells become significant, and whole blood can no longer be modeled as a continuum. When the diameter of the blood vessel is just slightly larger than the diameter of the red blood cell the Fahraeus–Lindquist effect occurs and there is a decrease in wall shear stress. However, as the diameter of the blood vessel decreases further, the red blood cells have to squeeze through the vessel and often can only pass in a single file. In this case, the inverse Fahraeus–Lindquist effect occurs and the wall shear stress increases.An example of a gaseous biofluids problem is that of human respiration. Recently, respiratory systems in insects have been studied for bioinspiration for designing improved microfluidic devices.Biotribolog Biotribology is the study of friction, wear and lubrication of biological systems especially human joints such as hips and knees.[5] In general, these processes are studied in the context of Contact mechanics and tribology.When two surfaces rub against each other, the effect of that rubbing on either surface will depend on friction, wear and lubrication at the point of contact. For example, the femoral and tibial components of knee implants routinely rub against each other during daily activity such as walking or stair climbing. If the performance of the tibial component needs to be analyzed, the principles of contact mechanics and tribology are used to determine the wear performance of the implant and the lubrication effects of synovial fluid. Additional aspects of biotribology include analysis of subsurface damage resulting from two surfaces coming in contact during motion, i.e. rubbing against each other, such as in the evaluation of tissue-engineered cartilage.