Sun21November1151AM 3

Assuming laminar flow, the resistance to blood flow in a blood vessel:

True / False

Depends on the thickness of the vessel wall Incorrect answer selected

Is inversely proportional to the fourth power of the radius of the vessel Correct

Depends on the haematocrit Correct

Is directly proportional to the length of the vessel Correct

Is directly proportional to the pressure drop along the vessel Incorrect answer selected

Explanation

This question refers to Poiseuille's Law.

R = P/Q = P/ (P r4/ I n)

Rearranging equation: R = 1/(P r4/ I n), therefore R a I n/r4

P is the pressure gradient along the vessel

Q is the volume flow rate

r is the radius of the vessel

n is the viscosity (haematocrit) of the blood

l is the length of the blood vessel.

Thickness of the vessel wall does not affect blood flow, but the stiffness of the vessel wall does affect blood flow.

Answer Statistics

Not enough data to display the statistics

Average score: 71.24%

Times answered: 251