19. The Blood Vessels

Introduction to Hemodynamics

19. The Blood Vessels

Introduction to Hemodynamics

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Multiple Choice

Assuming each of these blood vessels have the same difference in pressure along their length, which would have the lowest resistance and therefore, the greatest rate of blood flow?

Verified step by step guidance

To determine which blood vessel has the lowest resistance and greatest rate of blood flow, we need to consider Poiseuille's Law, which describes the flow of fluid through a cylindrical pipe.

Poiseuille's Law states that the flow rate (Q) is directly proportional to the fourth power of the radius (r) of the vessel and the pressure difference (ΔP), and inversely proportional to the length (L) of the vessel and the viscosity (η) of the fluid. The formula is:

Q = \frac{π r^{4} ΔP}{8 η L}

Since the pressure difference is the same for all vessels, we focus on the radius. The vessel with the largest radius will have the lowest resistance and therefore the greatest flow rate.

Examine the images of the blood vessels provided. Compare the diameters visually to determine which vessel has the largest radius.

Select the vessel with the largest radius as the one with the lowest resistance and greatest rate of blood flow.

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