Which of the following is NOT a determinant of resistance to flow?

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Multiple Choice

Which of the following is NOT a determinant of resistance to flow?

Resistance to flow in a vessel is governed by Poiseuille's law, which shows that resistance is proportional to viscosity and vessel length, and inversely proportional to the fourth power of the radius: R ∝ μL / r^4. This means viscosity and length increase resistance, while a small change in radius has a huge effect because of the r^4 term. Density does not appear in this relationship, so it does not set the steady, viscous resistance to flow. Density can influence inertial or pulsatile effects during unsteady flow, but for the basic resistance under steady laminar conditions, it does not determine resistance.

Resistance to flow in a vessel is governed by Poiseuille's law, which shows that resistance is proportional to viscosity and vessel length, and inversely proportional to the fourth power of the radius: R ∝ μL / r^4. This means viscosity and length increase resistance, while a small change in radius has a huge effect because of the r^4 term. Density does not appear in this relationship, so it does not set the steady, viscous resistance to flow. Density can influence inertial or pulsatile effects during unsteady flow, but for the basic resistance under steady laminar conditions, it does not determine resistance.

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