Theory 50/Biology & physiology/Blood viscosity
Viscosity Is Cells Against Vessel
The claim
Blood viscosity is set by the ratio of haematocrit to vessel diameter, so the same blood is thinner in capillaries than in arteries.
01Mechanism
Cells migrate toward the axis in small vessels, lowering apparent viscosity.
02Prediction
Viscosity should track the ratio.
03Refutation
Viscosity tracking haematocrit alone would remove diameter.