Question

Use the data describing blood flow in the circulatory system from the table below, and assume a typical blood flow rate of 5.0 L per minute.

	Aorta	Arteries	Arterioles	Capillaries	Venules	Veins	Vena cava
Diameter (cm)	2	0.5	0.002	0.0009	0.003	0.5	3
Total area (cm2)	3	20	500	4000	3000	80	7

Part A

What is the flow speed in the arterioles?

Express your answer with the appropriate units.

Part B

What is the pressure difference across a 1.0 cm length of arteriole?

Express your answer to two significant figures and include the appropriate units.

Answer 1

Part A

Flow speed, v = Q/A

where Q is flow rate and A is area

so,

Q = 5 L/min = 8.333e-5 m³ / s and A = 500 cm² = 500e-4 m²

v = 8.333e-5 / 500e-4

v = 1.67e-3 m/s

or

v = 1.7e-3 m/s

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Part B

Pressure difference can be found using Hagen Poiseuille theorem

Q = pi*P*r⁴ / 8nL

where n is viscosity of blood ( not given in the question)

L is length = 1 cm = 0.01 m

r is radius = 0.002 / 2 = 0.001 cm = 1e-5 m

Q = 8.333e-5 m³ / s

so,

P = 8nLQ / pi*r⁴

just put all the values and solve....it is simple plug and solve.

There are so many different values of viscosity, that's why i am giving you the equation...all you have to do is just put in the values.