Chapter 14, Problem 53GP

& BIO Essential hypertension Suppose your uncle has hypertension that causes the radii of his 40,000,000 arterioles to decrease by 20%. Each arteriole initially was 0.010 mm in radius and 1.0 cm long. By what factor does the resistance $R=8\mathrm{**\#x03B7;}l/\pi r^4$ to blood flow through an arteriole change because of these decreased radii? The pressure drop across all of the arterioles is about 60 mm Hg. If the flow rate remains the same, what now is the pressure drop change across the arteriole part of the circulatory system?