Editing Biomechanics (section)

=== Biofluid mechanics ===
[[File:Redbloodcells.jpg|right|thumb|[[Red blood cell]]s]]

Biological fluid mechanics, or biofluid mechanics, is the study of both gas and liquid fluid flows in or around biological organisms. An often studied liquid biofluid problem is that of blood flow in the human cardiovascular system. Under certain mathematical circumstances, [[blood]] flow can be modeled by the [[Navier–Stokes equations]]. ''In vivo'' [[whole blood]] is assumed to be an incompressible [[Newtonian fluid]]. However, this assumption fails when considering forward flow within [[arterioles]]. 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. Respiratory systems in insects have been studied for [[bioinspiration]] for designing improved microfluidic devices.<ref>{{cite journal | last1=Aboelkassem | first1=Yasser | year=2013 | title=Selective pumping in a network: insect-style microscale flow transport | journal=Bioinspiration & Biomimetics | volume=8 | issue=2 | pages=026004 | doi=10.1088/1748-3182/8/2/026004| pmid=23538838 |bibcode=2013BiBi....8b6004A | s2cid=34495501 }}</ref>