1. DISORDERS OF BLOOD FLOW AND
BLOOD PRESSURE
7/1/2014 1
Yofesi Isaac Obonyo
Nursing Science
Student

2. LEARNING OBJECTIVES
• Discuss at least three major properties of endothelial
cells and their associated functions/factors.
• List the five types of lipoproteins and state their
function in terms of lipid transport and development
of atherosclerosis.
• Describe the role of low-density lipoprotein receptors
in removal of cholesterol from the blood.
• Cite the criteria for diagnosis of hypercholesterolemia.
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3. LEARNING OBJECTIVES
• List the vessels most commonly affected by atherosclerosis
and describe the vessel changes that occur.
• Describe possible mechanisms involved in the development
of atherosclerosis.
• List risk factors for atherosclerosis.
• Describe the role of inflammation in the development of
atherosclerosis and how it can be assessed clinically.
• State the signs and symptoms of acute arterial occlusion.
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4. LEARNING OBJECTIVES
• Describe the pathology associated with the vasculitides
and relate it to four disease conditions associated with
vasculitis.
• Compare the manifestations of ischemia associated
with peripheral arterial disease, Raynaud
phenomenon, and thromboangiitis obliterans.
• Distinguish between the pathology and manifestations
of aortic aneurysms and dissection of the aorta.
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5. ARTERY STRUCTURE
Tunica intima: Endothelium
Tunica media: smooth muscle
Tunic adventitia: collagen and
elastic fibers
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6. QUESTION
Which vessel layer can expand to
accommodate pressure changes?
a. Tunica intima
b. Tunica media
c. Tunica adventitia
d. Tunica externa
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7. ANSWER
b. Tunica media
The tunica media is composed of smooth
muscle, which can stretch/expand to
accommodate changes in blood pressure.
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8. VASCULAR ENDOTHELIUM
• Food and O2 pass into tissues
• Wastes and CO2 pass from tissues into blood
• Creates compounds that cause vasodilation
or vasoconstriction
• Creates growth factors that can stimulate
smooth muscle
• Forms a smooth lining of the blood vessels
that resists clot formation
• Creates compounds to promote clot
formation in injured areas
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9. ATHEROSCLEROSIS
• Lipids get into the vascular endothelium
• White blood cells try to clear them away 
foam cells
• WBCs and vascular endothelium release
growth factors that promote plaque formation
• Plaques block the arteries
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10. LIPOPROTEINS
• The more protein, the
higher the density
• The more lipid, the
lower the density
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11. 7/1/2014 11

12. QUESTION
Tell whether the following statement is true or
false:
LDL is considered to be “good” cholesterol.
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13. ANSWER
False
LDL (low density lipoproteins) has more lipids
and less protein—it’s the “bad” cholesterol.
HDL (high density) has more protein and less
fat—it’s considered “good” cholesterol.
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14. LIPID TRANSPORT IN THE BODY
• Dietary lipids absorbed as chylomicrons
• Adipose and muscle cells take up lipids
from chylomicrons
• Chylomicron remnants are intermediate-
density lipoproteins
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15. LIPID TRANSPORT IN THE BODY
• IDLs become low-
density lipoproteins
(“bad cholesterol”)
• These can deliver fat to
the liver and by other
tissues
• LDL receptors are
necessary for the liver
to take them up
• Some LDLs are taken up
by scavenger cells like
macrophages
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16. FATTY STREAKS AND ATHEROSCLEROTIC
PLAQUES
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17. ATHEROSCLEROSIS
• Atherosclerosis develops because scavenger
cells encounter the fatty deposits in the artery
lining and
– Try to destroy the fats by oxidizing them
• Oxidized fats injure the endothelium
• Clots form and release growth factors
• Smooth muscle grows over the fatty core
– Try to remove the fats by eating them
• Become “foam cells” in the core of the plaque
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18. SCENARIO
A man has several genetic defects in his lipoprotein
receptors…
• His liver lacks LDL receptors
• His muscle cells lack receptors for the apoproteins on
chylomicrons
• His scavenger cells have extra LDL receptors
Question:
• Why might he develop atherosclerosis?
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19. STABLE PLAQUES
• Have thick fibrous caps
• Partially block vessels
• Do not tend to form clots or emboli
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20. UNSTABLE PLAQUES
• Have thin fibrous caps
• Plaque can rupture and cause a clot to form
• May completely block the artery
• The clot may break free and become an
embolus
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21. QUESTION
What immediate threat do unstable plaques
present?
a. Clot formation will increase pressure in the
vessel.
b. Plaque may lead to angina (chest pain).
c. Clots may break loose and block blood flow to
key organs.
d. All of the above constitute immediate threats.
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22. Answer
c. Clots may break loose and block blood flow to
key organs.
If a clot breaks loose, becoming an embolus,
it may lodge in a blood vessel to the brain,
heart, or lungs. When blood flow is
significantly decreased or blocked altogether,
the result is tissue death—in the examples
here, stroke, heart attack, or pulmonary
embolus. The other choices represent more
long-term/chronic problems.
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23. SCENARIO
A woman complains of pain in her left leg…
• Her foot is cool and pale
• She reports that it is often red and warm
when she is sitting down
• The pain occurs when she is walking to
church on Sundays
• The skin on her left leg is shinier than on the
right leg
Question:
• What could have caused all this? How?
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24. ANEURYSMS
• Wall of artery
weakens and
stretches
• Risk of rupture and
hemorrhage
• Risk of clot
formation
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25. DISCUSSION
How would each of the following affect blood
pressure?
• Vasodilation
• Decreased stretching of baroreceptors
• Hypoxemia
• Inhibiting angiotensin-converting enzyme
• Beta blockers
• α2 agonists
• Calcium channel blockers7/1/2014 25