Due to an atheromatous plaque, a man’s coronary artery has narrowed to one third of its healthy diameter, all other things being equal, his blood flow rate (ml/min) in that artery would A. be one third of the unobstructed value B. be one eighty-first of its healthy value C. be one ninth of its healthy value D. be one twenty-seventh of its healthy value
Option B. Poiseuille’s law states that volume flow rate is proportional to radius to the fourth power, so blood flow rate would be one eighty-first of its healthy value.
