(adsbygoogle = window.adsbygoogle || []).push({}); 1. The problem statement, all variables and given/known data

The red blood cell is very oddly shaped, and it is natural to wonder why it

is not spherical. This question should tell you the answer. Since the body

requires a certain minimum amount of hemoglobin in the blood (and hence a

certain minimum red cell volume), let us consider the red cell volume to be

fixed at 98 μm3.

(a) If the red blood cell were spherical, what is the smallest pore that it could

fit through? Assume that the red blood cell membrane will rupture if

stretched (a very good approximation) and remember that a sphere is the

geometrical object having minimum surface area for a given volume.

(b) Now consider the real shape of a red blood cell and allow the cell to

deform as it passes through a pore of radius R (Fig. 3.18). Assume that

the red blood cell is cylindrical with hemispherical ends. Taking cell

membrane area as 130 μm2, what is the minimum R value? You will get

a cubic equation for R; solve it numerically.

(c) Why is it advantageous to have non-spherical red blood cells?

2. Relevant equations

3. The attempt at a solution

Can't even begin since professor didn't teach anything..

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# Homework Help: Hemodynamic help please!

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