Chapter 7 Blood Vessels

Question 1

What two circulation system can increased blood pressure be seen?

Answer 1

Pulmonary and systemic

Question 2

What is systemic HTN defined by and what two types is it divided into?

Answer 2

BP >140/90

divided into primary and secondary

Question 3

What is systolic pressure a function of?

Answer 3

Stroke Volume

Question 4

What is diastolic pressure a function of?

Answer 4

TPR

Question 5

What are 6 risk factors from Primary HTN?

Answer 5

Age
race (increase in blacks, decreases in asians)
Obesity
Stress
lack of physical activity
high salt diet

Question 6

What is primary HTN due to? and what percentage of HTN cases does it encompass?

Answer 6

Unknown etiology

95%

Question 7

What percentage of HTN cases are secondary?

Answer 7

5%

Question 8

Describe how Renal artery stenosis leads to renovascular HTN

Answer 8

Stenosis decreases renal blood flow. JGA responds by secreting renin, which converts angiotensinogen to angiotensin 1. AT 1 gets converted to AT 2 by ACE in lungs. AT 2 raises BP

Question 9

How does AT 2 raise BP? 2 ways

Answer 9

1 contracting arteriolar smooth muscle and increasing TPR

2 Promoting adrenal release of aldosterone, which increased reabsorption of sodium in the DCT and CD.

Question 10

What signs are seen in renovascular HTN?

Answer 10

Increased plasma renin and unilateral atrophy (due to low blood flow) of the affected kidney; neither feature is seen in primary HTN.

Question 11

What are two important causes of stenosis in secondary HTN, and what demographic are they seen in?

Answer 11

atherosclerosis (elderly males) and fibromuscular dysplasia (young females)

Question 12

What is fibromuscular dysplasia? What size vessels, what common vessel?

Answer 12

Developmental defect of the blood vessel wall, resulting in irregular thickening of large and medium sized arteries, especially the renal artery.

Question 13

Describe benign HTN and its symptoms and pathophys.

Answer 13

a mild to moderate elevation in BP; most cases of HTN are benign. Clinically silent; vessels and organs are damaged slowly over time

Question 14

Describe malignant HTN, how common it is, how it arises, and its symptoms and its effects on BV?

Answer 14

Severe elevation in BP (>180/120 or >200/120); comprises <5% of HTN cases. It may arise from preexisting benign HTN or de novo. Presents with acute end organ damage (eg acute renal failure, HA, and papilledema) and is a medical emergency. Can also cause fibrinoid necrosis of BV walls.

Question 15

What is Arteriosclerosis and what are the three pathological patterns?

Answer 15

literally “hard arteries” due to thickening of the blood vessel wall.
Atherosclerosis
Arteriolosclerosis
Monckeberg medial calcific sclerosis

Question 16

What is atherosclerosis?

Answer 16

Intimal plaque that obstructs blood flow. Consists of a necrotic lipid core (mostly cholesterol) with a fibromuscular cap; often undergoes dystrophic calcification.

Question 17

What size arteries does atherosclerosis affect? What are the 4 most common

Answer 17

involves large and medium sized arteries; abdominal aorta, coronary artery, popliteal artery, and internal carotid artery are commonly affected.

Question 18

What 4 modifiable risk factors of atherosclerosis?

Answer 18

HTN, hypercholestremia, smoking, diabetes

Question 19

What are 3 non modifiable risk factors for atherosclerosis?

Answer 19

age (number and severity of lesions increases with age)
gender( increased risk in males and postmenopausal females; estrogen is protective)
genetics (multifactorial, but family history is highly predictive of risk)

Question 20

Describe the pathogenesis of atherosclerosis?

Answer 20

1 damage to endothelium allows lipids to leak into intima
2 lipids are oxidized and then consumed by macrophages via scavenger receptors resulting in foam cells
3 Inflammation and healing leads to deposition of extracellular matrix and proliferation of smooth muscle and fibromuscular capsule

Question 21

Describe the morphological stages of atherosclerosis?

Answer 21

1 Begins as fatty streaks (flat yellow lesions of the intima consisting of lipid laden macrophages); arise early in life (present in most teenagers)
2 progresses to atherosclerotic plaques.

Question 22

What are 4 complications of atherosclerosis?

Answer 22

1 stenosis of medium sized vessels results in impaired blood flow and ischemia leading to peripheral vascular disease (lower extremity arteries), angina (coronary arteries), ischemic bowel disease (mesenteric arteries)
2 Plaque rupture with thrombosis results in MI )coronary arteries) and stroke (Middle cerebral arteries)
3 Plaque rupture with embolization results in atherosclerotic emboli, characterized by cholesterol crystals within the embolus (Cholesterol clefts)
4 Weakening of vessel wall results in aneurysm (abdominal aorta) due to diffusion barrier causing media and adventitia to become weak and atrophic

Question 23

What is arteriolosclerosis, what two types is it divided into?

Answer 23

Narrowing of small arterioles; divided into hyaline and hyperplastic types

Question 24

What is hyaline ateriolosclerosis caused by and what can be seen on microscopy??

Answer 24

caused by proteins leaking into the vessel wall, producing vascular thickening; proteins are seen as pink hyaline on microscopy

Question 25

What two conditions is hyaline arteriolosclerosis a consequence of? what is the etiology of each?

Answer 25

Long standing benign HTN - high blood pressure forces protein into the wall Diabetes - non enzymatic glycosylation damages BM and makes it leaky and proteins get into wall.

Question 26

What does hyperplastic arteriolosclerosis involve? What is the classic appearance?

Answer 26

Thickening of vessel wall by hyperplasia of smooth muscle (onion skin appearance)

Question 27

What size vessels does arteriolosclerosis effect?

Answer 27

small

Question 28

What does hyaline arteriolosclerosis result in?

Answer 28

reduced vessel caliber with end organ ischemia; classically produces glomerular scarring (arteriolonephrosclerosis) that slowly progresses to chronic renal failure.

Question 29

What is the cause of hyperplastic arteriolosclerosis?

Answer 29

malignant HTN

Question 30

What does hyperplastic arteriolosclerosis result in?

Answer 30

Results in reduced vessel caliber with end-organ ischemia. may lead to fibrinoid necrosis of the vessel wall with hemorrhage; classically causes acute renal failure with a characteristic "flea bitten" appearance due to pinpoint hemorrhages.

Question 31

What is monckeberg calcific sclerosis? what are its symptoms?

Answer 31

calcification of the media of muscular (medium sized) arteries; nonobstructive. Not clinically significant; seen as an incidental finding on x-ray or mammography

Question 32

What is an Aortic dissection?

Answer 32

Intimal tear with dissection of blood though the media of the aortic wall

Question 33

Where do aortic dissections typically occur?

Answer 33

Occurs in the proximal 10 cm of the aortic (high stress region) with preexisting weakness of the media.

Question 34

What are two common causes of weakness of the media leading to aortic dissection?

Answer 34

1 Hypertension results in hyaline ateriolosclerosis of the vasa vasorum; decreased flow causes atrophy of the media 2 Marfan Syndrome (fibrillin) and Ehler's Danlos (Collagen) syndrome classically lead to weakness of the connective tissue in the media (cystic medial sclerosis)

Question 35

How does aortic dissection present?

Answer 35

Presents as sharp, tearing chest pain that radiates to the back

Question 36

What complications can arise from aortic dissection?

Answer 36

complications include pericardial tamponade ( dissection goes back toward heart, most common cause of death), rupture with fatal hemorrhage, and obstruction of branching arteries (eg. coronary or renal) with resultant end organ ischemia.

Question 37

What is a thoracic aneurysm?

Answer 37

Balloon-like dilation of the thoracic aorta

Question 38

What are thoracic aneurysm due to and what are they classically seen in? What is their classic gross appearance?

Answer 38

Due to weakness in the aortic wall. Classically seen in tertiary syphilis; endarteritis of the vaso vasorum results in luminal narrowing, decreased flow, and atrophy of the vessel wall. Results in a 'tree-bark' appearance of the aorta.

Question 39

What is a major complication in a thoracic aneurysm?

Answer 39

dialtion of the aortic valve root, resulting in aortic valve insufficiency

Question 40

What are some other complications of a thoracic aneurysm?

Answer 40

compression of mediastinal structures ( eg airway or esophagus) and thrombosis/embolism due to disruption of blood flow

Question 41

Where do abdominal aortic aneurysms usually occur?

Answer 41

Below the renal arteries and above the bifurcation.

Question 42

What is AAA primarily due to? who is it seen in?

Answer 42

Primarily due to atherosclerosis; classically seen in male smokers >60 years old with HTN. atherosclerosis increases the diffusion barrier to the media, resulting in atrophy and weakness of the vessel wall.

Question 43

How does AAA present?

Answer 43

pulsatile abdominal mass that grows with time

Question 44

What is a major compication of an AAA? what is the classic triad seen in this.

Answer 44

rupture, especially when >5 cm in diameter; presents with triad of hypotension, pulsatile abdominal mass, and flank pain

Question 45

What are some other complications of an AAA?

Answer 45

compression of local structures (eg ureter) and thrombosis/embolism

Question 46

What is a hemangioma? when does it usually present? what structures does it most often involve? does it blanch?

Answer 46

Benign tumor comprised of blood vessels. commonly present at birth; often regresses during childhood most often involves skin and liver Blanches

Question 47

What is an angiosarcoma? what are the common sites? what exposures can predispose?

Answer 47

Malignant proliferation of endothelial cells; highly aggressive. Common sites include skin, breast, and liver. Liver angiosarcoma is associated with exposure to PVC, arsenic, and thorotrast (old imaging dye)

Question 48

What is Kaposi sarcoma and what is it associated with? What grade malignancy is it?

Answer 48

Low grade malignant proliferation of endothelial cells; associated with HHV-8

Question 49

How does Kaposi sarcoma present?

Answer 49

presents as purple pathces, plaques, and nodules on the skin; may also involve visceral organs

Question 50

What three populations is kaposi sarcoma classically seen in? how does it present and how is it treated?

Answer 50

1 Older Eastern European males - tumor remains localized to skin; treatment involves surgical removal 2 AIDS- tumor spreads early; treatment is antiretroviral agents (to boost immune system) 3 Transplant recipients - tumor spreads early; treatment involves decreasing immunosuppresion.