1. Chapter 18 Disorders of Blood Flow and Blood Pressure
Essentials of Pathophysiology
Chapter 18 Disorders of Blood Flow and Blood Pressure

2. PRE-LECTURE QUIZ True/False F HDL is known as the “bad cholesterol.”
T Most abdominal aneurysms are asymptomatic.
F Essential (primary) hypertension is characterized by chronic elevation in blood pressure that results from some other disorder, such as kidney disease.
 F Orthostatic or postural hypotension is an abnormal rise in blood pressure that occurs when assuming the standing position from the supine position.
T Venous insufficiency leads to tissue congestion and edema in the lower extremities. 

3. PRE-LECTURE QUIZ
Aortic
The __________ controls the transfer of molecules across the vascular wall, plays a role in platelet adhesion and blood clotting, and functions in the modulation of blood flow and vascular resistance.
__________, with its associated risk for the development of atherosclerosis, is a major cause of cardiovascular disease. 
__________ phenomenon is a functional disorder caused by intense vasospasm of the arteries and arterioles in the fingers and, less often, in the toes. 
__________ dissection is an acute, life-threatening condition that involves hemorrhage into the vessel wall with longitudinal tearing or separation of the vessel wall to form a blood-filled channel. 
The body uses neural mechanisms and humoral mechanisms to effect the __________-term regulation of blood pressure, which occurs over minutes or hours and is intended to correct temporary imbalances in blood pressure.
Endothelium
Hyperlipidemia
Raynaud
Short

4. Artery Structure Arranged in tunics or coats
Tunica intima: Endothelium
Tunica media: smooth muscle
Tunic adventitia: collagen and elastic fibers
Author: Add text?

5. Artery Structure Tunica intima: endothelium
Tunica media: smooth muscle
Tunica adventitia: collagen and elastic fibers

6. Question
Which vessel layer can expand to accommodate pressure changes?
Tunica intima
Tunica media
Tunica adventitia
Tunica externa

7. Answer
Tunica media
The tunica media is composed of smooth muscle, which can stretch/expand to accommodate changes in blood pressure.
Is this answer arguable?

8. Vascular Endothelium
Nutrients 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

9. Lipids get into the vascular endothelium
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

10. The more protein, the higher the density
Lipoproteins
The more protein, the higher the density
The more lipid, the lower the density

11. Lipoproteins The more protein, the higher the density
The more lipid, the lower the density
i.e. protein is heavier than lipids

12. Question
Tell whether the following statement is true or false. LDL is considered to be “good” cholesterol.

13. Answer
False Rationale: LDL (low-density lipoprotein, which has more lipids and less protein) is the “bad” cholesterol. HDL (high-density lipoprotein) has more protein and less fat, and is considered “good” cholesterol.

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, IDL

15. Lipid Transport in the Body (cont.)
IDLs become low-density lipoproteins (“bad cholesterol”)
These can deliver fat to the liver and to other tissues
LDL receptors are necessary for the liver to take them up
Some LDLs are taken up by scavenger cells like macrophages

16. Fatty Streaks and Atherosclerotic Plaques

17. Fatty Streaks and Atherosclerotic Plaques

18. 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

19. Lipid Transport in the Body
High-density lipoproteins (“good cholesterol”) are made in the liver
They go out to the peripheral tissues and pick up lipid
Then they carry it back to the liver

20. 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?

21. Stable Plaques
Have thick fibrous caps
Partially block vessels
Do not tend to form clots or emboli

22. 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

23. Question
What immediate threat do unstable plaques present?
Clot formation will increase pressure in the vessel.
Plaque may lead to angina (chest pain).
Clots may break loose and block blood flow to key organs.
All of the above constitute immediate threats.

24. Answer
c. Clots may break loose and block blood flow to key organs. Rationale: 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.

25. 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 her right leg
Question:
What could have caused all this? How?

26. Aneurysms Wall of artery weakens and stretches
Risk of rupture and hemorrhage
Risk of clot formation

27. Aortic Arch Aneurysm

28. Carotid Artery Aneurysm

29. Discussion How would each of the following affect blood pressure?
Vasodilation
Decreased stretching of baroreceptors
Hypoxemia
Inhibiting angiotensin-converting enzyme
Beta blockers
Alpha-2 agonists
Calcium-channel blockers
Lower resistance lowers BP
Reflex raises BP
Calls for more blood flow raises BP
Blocks formation of Angiotesion II Lowers BP
Slows HR Lowers BP
Decreases Sympathetic response Lowers BP
Decreases vascular resistance Lowers BP

30. Varicose Veins

31. 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?

32. Aneurysms Wall of artery weakens and stretches
Risk of rupture and hemorrhage
Risk of clot formation