Quick Study Index, Module 6


"Hemodynamics is the study of the movement of the blood and the forces concerned therein."

Transmural pressure
Perfusion pressure


Blood velocity
Velocity, diameter, wall shear and Reynolds number (Table 5.01)

Shear rate
Pressure / Velocity Equation

Inter-dependence of velocity and pressure (Figure 5.01)
Example of Bernoulli's Principle in the circulation (Figure 5.02)

Think in terms of Total Fluid Energy!

Components of total energy of a moving liquid (per unit volume)

Total fluid energy


Hydrostatics (Figure 5.03)

Components of "hydrostatic" pressure
Amount and relative importance of kinetic energy in different parts of the circulation (Table 5.02)
Blood pressure changes with postural change (Figure 5.04)
Postural effects on blood pressure
Gravity effects: Summary

Poiseuille equation

Factors determining blood viscosity

Factors limiting the usefulness of the Poiseuille equation to the cardiovascular system
Newtonian fluid

Relative viscosity
Flow rate in distensible vs. non-distensible tubes (Figure 5.05)


Classes of vascular resistance
Resistance: The equation
Peripheral resistance units

Clinical resistance measurements

Normal clinical resistance values
Total resistance in series and parallel circuits (Figure 5.06)
Relative resistance to flow in the vascular bed (Table 5.03)


Right: Drawing from William Harvey, Treatise on the Circulation (demonstrating valves in the superficial veins)



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