Discover a world of knowledge and get your questions answered at IDNLearn.com. Find reliable solutions to your questions quickly and accurately with help from our dedicated community of experts.

55) A typical arteriole has a diameter of 0.080 mm and carries blood at the rate of 9.6×10^−5 cm3/s. (a) What is the speed of the blood in an arteriole? (b) Suppose an arteriole branches into 8800 capillaries, each with a diameter of 6.0×10^−6 m. What is the blood speed in the capillaries? (The low speed in capillaries is beneficial; it promotes the diffusion of materials to and from the blood.)

Sagot :

ANSWER:

a) 1.91 cm/s

b) 0.039 cm/s

STEP-BY-STEP EXPLANATION:

a)

Here, since we need the velocity in cm/s, we assume that a small volume of blood passes through the section of the arteriole in a given time.

So, we have to divide the blood flow by the area of the arteriole section, therefore:

[tex]A=\pi\cdot\mleft(\frac{d}{2}\mright)^2[/tex]

d = 0.08 mm = 0.008 cm

Replacing:

[tex]A=3.14\cdot\mleft(\frac{0.008}{2}\mright)^2=0.00005024=5.024\cdot10^{-5}cm^2[/tex]

We calculate the speed by dividing the rate by the previous calculated area, like this:

[tex]\begin{gathered} v=\frac{q}{A} \\ \text{Replacing} \\ v=\frac{9.6\cdot10^{-5}}{5.024\cdot10^{-5}} \\ v=1.91\text{ cm/s} \end{gathered}[/tex]

b)

First we find the area of the section of the capillaries:

[tex]\begin{gathered} d=6\cdot10^{-6}m=6\cdot10^{-4}cm \\ R\text{eplacing} \\ A=3.14\cdot\mleft(\frac{6\cdot10^{-4}}{2}\mright)^2 \\ A=0.0000002826=2.826\cdot10^{-7}cm^2 \end{gathered}[/tex]

Now we have to remember that the flow is dividid in equal parts, so the volume by seconds is:

[tex]\begin{gathered} q=\frac{9.6\cdot10^{-5}}{8800} \\ q=1.09\cdot10^{-8}\frac{cm^3}{s} \end{gathered}[/tex]

So the speed in this case is:

[tex]\begin{gathered} v=\frac{q}{A} \\ v=\frac{1.09\cdot10^{-8}}{2.826\cdot10^{-7}} \\ v=0.039\text{ cm/s} \end{gathered}[/tex]

This latter speed is less than in the main arteriole.

We appreciate every question and answer you provide. Keep engaging and finding the best solutions. This community is the perfect place to learn and grow together. Your search for answers ends at IDNLearn.com. Thank you for visiting, and we hope to assist you again soon.