An arteriole has a radius of 25 m and it is 1000 m long. The viscosity of blood is 3 x 10-3 Pa s and its density is 1.055 g cm-3. Assume the arteriole is a right circular cylinder. A. Assuming laminar flow, what is the resistance of this arteriole?

Respuesta :

To solve this problem it is necessary to apply the concepts related to the Hagen-Poiseuille equation law, which is a physical equation for the description of nonideal fluid dynamics, that is the pressure drop in an incompressible and Newtonian fluid in laminar flow flowing through a long cylindrical pipe of constant cross-section.  The expression can be extrapolated to the calculation of resistance through an analogy of Ohm's law. Mathematically the equation that describes this phenomenon can be described as,

[tex]R = \frac{8\mu L}{\pi R^4}[/tex]

Where,

R = Resistance

L = Length of pipe

[tex]\mu =[/tex] Dynamic viscosity

R = Pipe radius

Our values are given as,

[tex]\mu = 3*10^{-3}Pa\cdot s[/tex]

[tex]L = 1000*10^{-6}m[/tex]

[tex]R = 25*10^{-6}m^4[/tex]

Replacing at the previous equation we have,

[tex]R = \frac{8(3*10^{-3})(1000*10^{-6})}{\pi (25*10^{-6})^4}[/tex]

[tex]R = 1.9556*10^{13}Pa\cdot s/m^3[/tex]

Therefore the resistance of this arteriole is [tex]1.9556*10^{13}Pa\cdot s/m^3[/tex]