CH7 - Arteriosclerosis Flashcards
What is arteriosclerosis?
Literally, hard arteries; due to thickening of the blood vessel wall
What are the three pathologic patterns for arteriosclerosis ?
atherosclerosis, arteriolosclerosis, and Monckeberg medial calcific sclerosis
What is atherosclerosis?
Intimal plaque that obstructs blood flow
What does atherosclerosis consists of?
a necrotic lipid core (mostly cholesterol) with a fibromuscular cap, often undergoes dystrophic calcification
What does atherosclerosis involve?
large- and medium-sized arteries; abdominal aorta, coronary artery, popliteal artery, and internal carotid artery are commonly affected.
How are the risk factors for atherosclerosis divided?
into modifiable and nonmodiliable.
What are modifiable risk factors for atherosclerosis?
it includes hypertension, hypercholesterolemia (LDL increases risk; HDL decreases risk), smoking, and diabetes.
What are nonmodifiable risk factors for atherosclerosis?
Age, gender, genetics
How does age affect atherosclerosis?
number and severity of lesions increase with age
How does gender affect atherosclerosis?
increased risk in males and postmenopausal females; estrogen is protective
How does genetics affect atherosclerosis?
multifactorial, but family history is highly predictive of risk
What is the pathogenesis of atherosclerosis?
Damage to endothelium allows lipids to leak into the intima. 2. Lipids are oxidized and then consumed by macrophages via scavenger receptors, resulting in foam cells. Inflammation and healing leads to deposition of’extracellular matrix and proliferation o
What are fatty streaks?
flat yellow lesions of the intima consisting of lipid-laden macrophages
What are the morphologic stages in atherosclerosis?
1) Begins as fatty streaks; arise early in life (present in most teenagers) 2) Progresses to atherosclerotic plaque
What are the complications of atherosclerosis?
1) Stenosis of medium sized vessels 2) plaque rupture 3) weakening of vessel wall
What accounts for >50% of disease in Western countries?
complications of atherosclerosis
What does stenosis of medium-sized vessels result in?
impaired blood flow and ischemia
What does stenosis lead to? (what arteries are involved)
i. Peripheral vascular disease (lower extremity arteries, e.g., popliteal) ii. Angina (coronary arteries) iii. Ischemic bowel disease (mesenteric arteries)
In atherosclerosis, what does plaque rupture with thrombosis results in?
myocardial infarction (coronary arteries) and stroke (e.g., middle cerebral artery)
In atherosclerosis, what does plaque rupture with embolization result in?
atherosclerotic emboli, characterized by cholesterol crystals within the embolus
In atherosclerosis, what does weakening of vessel wall result in?
aneurysm (e.g., abdominal aorta)
What is arteriolosclerosis?
Narrowing of small arterioles
What is arteriolosclerosis divided into?
hyaline and hyperplastic types
What is hyaline arteriolosclerosis caused by?
proteins leaking into the vessel wall, producing vascular thickening;
In hyaline arteriolosclerosis what is seen on microscopy?
proteins are seen as pink hyaline on microscopy
Hyaline arteriolosclerosis is a consequence of what?
long-standing benign hypertension or diabetes
What does hyaline arteriolosclerosis result in?
reduced vessel caliber with end-organ ischemia
What does hyaline arteriolosclerosis classically produce?
glomerular scarring (arteriolonephrosclerosis) that slowly progresses to chronic renal failure
What is hyperplastic arteriolosclerosis?
it involves thickening of vessel wall by hyperplasia of smooth muscle onion-skin appearance
What is hyperplastic arteriolosclerosis a consequence of?
malignant hypertension
What does hyperplastic arteriolosclerosis result in?
reduced vessel caliber with end-organ ischemia
What may hyperplastic arteriolosclerosis lead to?
fibrinoid necrosis of the vessel wall with hemorrhage
What does the fibrinoid necrosis in hyperplastic arteriolosclerosis classically cause and how does it appear?
acute renal failure with a characteristic flea-bitten appearance
What is monckeberg medial calcific sclerosis?
calcification of the media of muscular (medium-sized) arteries; nonobstructive
How does monckeberg medial calcific sclerosis present clinically?
Not clinically significant; seen as an incidental finding on x-ray or mammography
