Q1 - Poiseuille's Law and Blood Pressure Regulation
In mammals, a high blood pressure is needed to achieve a high blood flow (cardiac fluid flow) and to overcome any vascular resistance against the flow of blood. In order to make deductions about blood flow, Poiseuille’s Law is used (Fig.). Poiseuille’s Law: Q = fluid flow, V = volume, t = time, p = pressure, r = vessel radius, η = viscosity (constant for a given temperature and fluid type), L = vessel length, and R = flow resistance.
Using the information and data, determine which of the statements are true or which are false.
A. Assuming similar blood flow in a wide and a narrow artery of the same length, the change in mean blood pressure is greater in the former
B. Increased atherosclerosis leads generally to faster blood flow in the circulation
C. Comparing monozygotic twins, one living at sea level and the other at 3,000 m, the latter will have a higher resistance to blood flow
D. In a specific patient suffering from atherosclerosis, the radius of blood vessels on average had decreased by 1/6, which caused blood pressure to double to maintain the blood flow
Question reproduced from IBO 2015, Theoretical Exam A, licensed under CC BY-NC-SA 4.0 - attributed to the International Biology Olympiad. Open the full exam PDF · Community solutions (unofficial)