Poiseuille's Law of Blood Flow
A fluid dynamics equation governing laminar viscous fluid flow through a cylindrical vascular pipe.
Governing formula
Q = (π r⁴ ΔP) / (8 η L)
SI unit
m³/s or L/min (Volumetric Flow Rate)
In depth
Proves that volumetric flow rate Q is proportional to the fourth power of vessel radius r⁴. A 16% reduction in blood vessel radius cuts volumetric blood flow in half if pressure remains constant.
Examples in the real world
Atherosclerotic plaque narrowing coronary artery radius in half, reducing maximum blood flow by 93.75%.