Hemodynamics
The physical study of blood flow dynamics, vascular resistance, and pressure relations within the circulatory system.
Governing formula
Q = ΔP / R_v, R_v = (8 η L) / (π r⁴) (Poiseuille Flow)
SI unit
L/min (Cardiac Output) & mmHg (Pressure)
In depth
Blood is a non-Newtonian, shear-thinning suspension of red blood cells. Vascular resistance R_v is inversely proportional to the fourth power of vessel radius r⁴ (Poiseuille's law), making small arterial constriction major regulators of blood pressure.
Examples in the real world
Arterial vasoconstriction doubling vascular resistance to raise systemic blood pressure.