Biomedical Engineering Reference
In-Depth Information
HOMEWORK PROBLEMS
5.1
Blood is primarily actively transported through the venous system via
(a)
increasing the intravascular blood pressure
(b)
muscle contractions
(c)
venous valve system
(d)
b and c
5.2
Which of the following changes would have the most significant effect on increasing the
vascular resistance?
(a)
doubling the blood vessel diameter
(b)
halving the blood vessel length
(c)
doubling the blood viscosity
(d)
halving the blood vessel diameter
(e)
doubling the blood vessel length
5.3
Discuss the salient anatomical differences between arteries and veins, and detail how this
relates to the function of each blood vessel.
5.4
Why is the blood flow to some organs (such as the stomach, intestines) discontinuous and
the blood flow to other organs (such as the brain, heart) continuous?
5.5
The plasma component of blood contributes approximately ____ percent to the total blood
volume, of which water accounts for _____ percent of the total plasma volume.
5.6
Discuss the important proteins that are found in plasma. Why are the concentrations of
these proteins so tightly regulated?
5.7
Discuss coagulation and the role of platelets in the coagulation process.
5.8
When you are dehydrated, it would cause an (increase or decrease) in the hematocrit.
What effect would this have on blood flow, viscosity, blood pressure, etc?
5.9
The three cellular components of blood have different anatomical structures that relate to
their functions. Briefly discuss the important structures for each cellular component.
5.10
Calculate the difference in blood flow rate for a 5-cm section of a blood vessel with a pres-
sure difference of 25 mmHg that experiences an increase in blood flow diameter from
100
μ
m to 200
μ
m. Also calculate the blood flow rate for a constriction that reduces the
m. For each of these three cases, what is the vascular resistance?
5.11
When a patient experiences high blood pressure, discuss what happens to the vascular
flow rate. What changes must occur to allow the vascular flow rate return to normal con-
ditions? Assume that the peak systolic blood pressure for the hypertensive patient is
190 mmHg.
5.12
Calculate the wave propagation speed for a 100
diameter to 50
μ
m thick blood vessel with a radius of
10 mm. This blood vessel has a pressure of 85 mmHg and a Young's Modulus of 12.5 kPa.
Under disease conditions, the vascular wall can stiffen so that the Young's Modulus
approaches 30 kPa. Calculate the change in the wave speed under these conditions. What
blood vessel property is likely to change in response to the increase in stiffness and why?
*5.13
Model the pressure wave propagation at a branching junction where one parent vessel
branches into two daughter vessels (such as
Figure 5.13
). Assume that the diameter of the
parent branch is 100
μ
μ
m, the diameter of one daughter branch is 60
μ
m, and the diameter
of the other daughter branch is 45
μ
m. Assume that the thickness of each vessel is the
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