Blood flow

An interesting problem in hemorheology is to calculate that volume fraction of erythrocytes (hematocrit) that is optimal for transporting a maximum amount of oxygen. If the hematocrit is too low, too few erythrocytes are present to transport oxygen. If it is too high, the blood is very viscous and cannot flow quickly, so that oxygen supply to the tissues is again reduced. Stark & Schuster (2012)

* Formula Saitô (1950)

Hematocrit / Oxygen
10% / 57%  
40% / 100%  
60% / 86%  
90% / 25%  

We thank BruceBlaus (Wikimedia Commons) for blood cell images,
licensed under the Creative Commons Attribution 3.0 Unported license.