10) In chronic hypertension, vessel radius, r, is reduced due to a thickening of the vessel...

a) Here , it is given that

So, as r is reduced, 1/r^4 increases and R increases.

b) The equation for pressure gives that

So, as r reduces, 1/r^4 increases and the pressure difference increases.

c) It is given that

So,

Here, r' = r/3

r/r' = 3

So,

R'/R = 3^4 = 81

So,

R' = R x 81

For the change in pressure also, the relation is same.

So,

d) For a healthy adult, the pressure difference is 85 mm Hg

So,

using the equation above,