Chapter 11: Vascular Anomalies, HTN, Atherosclerosis, Aneurysms/Dissections Flashcards
In which layer of vessels will you find nerve fibers and the vasa vasorum (“vessels of the vessels”)?
Adventitia
Which type of vessel has an endothelial cell lining, no media, and variable number of pericytes?
Capillaries
In most inflammatory rxns, vascular leakage and leukocyte exudation occur via what vessels?
Post-capillary venules (veins)
All vessels except _______ share a 3-layered architecture consisting of an endothelium lined intima, a surrounding smooth m. media, and supportive adventititia.
Capillaries
Large or multiple AV fistulas may shunt blood from arterial or venous circulation, forcing the heart to pump additional volume and lead to what clinically significant event?
High-output cardiac failure
Fibromuscular dysplasia is a focal thickening in which arteries (size and type)?
Medium and large muscular arteries (i.e, renal, carotid, splanchnic, and vertebral)
Is there a genetic association with fibromuscular dysplasia and who is most often affected?
- First-degree relatives have ↑ incidence
- Most frequently in young women (NO assoc. w/ OC’s or ↑ estrogen)
Which layers of the vessel wall undergo hyperplasia and fibrosis in fibromuscular dysplasia?
Media and intima
Fibromuscular dysplasia of renal arteries can be a cause of?
Renovascular HTN
Endothelial dysfunction refers to an alteration in endothelial what?
Often has what 2 characteristics?
- Phenotype
- Often both proinflammatory and prothrombogenic
Alteration of endothelial phenotype seen in endothelial dysfunction is responsible for the initiation of what changes seen in pathological processes?
Initiation of thrombus formation, atherosclerosis, and vascular lesions of HTN
Vascular smooth m. cells have the capacity to proliferate when appropriately stimulated and can also synthesize what?
- Collagen
- Elastin
- Proteoglycans
- Elaborate cytokines and GF’s
What is the stereotypical response of the vessel wall to any insult?
Intimal thickening
Turbulent flow, HTN, cytokines, complement, bacterial/lipid prods., advanced glycation end-products, hypoxia, acidosis, viruses and cigarette smoke may cause endothelial activation which leads to increased/altered expression of what?
- Procoagulants, adhesion molecules, and pro-inflammatory cytokines
- Altered expression of chemokines, cytokines, and GF’s
Describe the 3 events in the stereotypical response to vascular injury.
- Recruitment of smooth m. cells or smooth m. precursor cells to intima
- Smooth m. cell mitosis
- Elaboration of extracellular matrix = intimal thickening
Secondary HTN is a result of an underlying disease in which organs?
- Renal –> renal a. stenosis
- Adrenal = 1’ aldosteronism, Cushing syndrome or pheochromocytoma, pregnancy induced
- CV = coarctation of aorta, polyarteritis nodosa
- Neuro = sleep apnea, acute stress, psychogenic
Which systolic and diastolic BP characterize malignant HTN?
>200/>120
Malignant HTN is often superimposed on what?
Pre-existing “benign” HTN
What are 5 cardiovascular causes of secondary HTN?
- Coarctation of aorta
- Polyarteritis nodosa
- Increased intravascular volume
- Increased cardiac output
- Rigidity of aorta
What are 4 neurologic causes of secondary HTN?
- Sleep apnea
- ↑ ICP
- Sleep apnea
- Acute stress, including surgery
Blood pressure is a product of _______ x________
Cardiac output x Peripheral Resistance
The most important determinant of stroke volume is what?
Regulated by?
- Filling pressure
- Regulated thru Na+ homeostasis (mineralocorticoids and ANP) and its effect on blood volume
How is cardiac output calculated?
CO = SV x HR
List the 5 humoral factors which are constrictors and have an effect on peripheral resistance?
- Angiotensin II
- Catecholamines
- Thromboxane
- Leukotrienes
- Endothelin
Peripheral resistance is regulated predominantly at the level of which vessels?
By which inputs?
- Arterioles
- Neural and hormonal inputs
What 2 relaxing substances are produced by the kidney to counterbalance the vasopressor effects of angiotensin?
- NO
- Prostaglandins
Explain the effects of renal artery stenosis and how they contribute to renovascular HTN?
- ↓ pressure in afferent arteriole = ↓ GFR
- ↑ Renin secretion = RAAS system activation = ↑ vascular tone and blood volume
Liddle syndrome is due to gain-of-function mutations in which protein and leads to what?
- ENaC protein
- Causes ↑ Na+ reabsorption in response to aldosterone
Gene defects in which enzymes involved in aldosterone metabolism lead to primary hyperaldosteronism and in turn secondary HTN?
- Aldosterone synthase
- 11β-hydroxylase
- 17α-hydroxylase
HTN is associated with what 2 forms of small blood vessel disease?
1) Hyaline arteriolosclerosis
2) Hyperplastic arteriosclerosis
Homogenous pink hyaline thickening with associated luminal narrowing is characteristic of?
Hyaline arteriosclerosis
What type of arteriosclerosis is associated with severe HTN and is often a component of malignant HTN?
Hyperplastic arteriosclerosis
Vessels exhibiting concentric, laminated (“onion-skin”) thickening of the walls with luminal narrowing is characteristic of?
Hyperplastic arteriosclerosis
Nephrosclerosis due to chronic HTN is a form of what type of arteriosclerosis?
Hyaline arteriosclerosis
What type of arteriosclerosis is a common feature of diabetic microangiography?
Hyaline arteriosclerosis
The laminations of hyperplastic arteriosclerosis are accompanied by what other morphological changes in malignant HTN?
- Fibrinoid deposits
- Vessel wall necrosis (necrotizing arteriolitis)
What do the laminations of hyperplastic arteriosclerosis consist of?
Smooth muscle cells w/ reduplicated BM
Monckeberg medial sclerosis most often occurs in which age group and is characterized by what?
Clinically significant?
- >50 yo
- Calcification of walls of muscular arteries, typically internal elastic membrane
- No narrowing of lumen and no clinical significance
What is the most frequent and clinically important pattern of arteriosclerosis?
Atherosclerosis
The likelihood of atherosclerosis is determined by the combination of which acquired and inherited risk factors?
- Acquired = cholesterol levels, smoking and HTN
- Inherited = LDL receptor gene mutations
What are in the intimal lesions seen in atherosclerosis and describe their morphology?
- Atheroma = atheromatous = atherosclerotic plaque
- Raised lesion w/ a soft grumous core of lipid covered by fibrous cap
Besides obstructing blood flow, atherosclerotic plaques can rupture leading to what?
Catastrophic obstructive vascular thrombosis
Which country is known to have the highest ischemic heart disease-associated mortality?
Soviet Union
What are the 5 major modifiable risk factors for atherosclerosis?
- Hyperlipidemia
- HTN
- Cigarette smoking
- Diabetes
- Inflammation
How do multiple risk factors present act in concert to increase risk of atherosclerosis?
Have a multiplicative effect = Synergism
Woman of which age are somewhat protected from atherosclerosis?
May due to effect of?
- Pre-menopausal woman
- Effect of estrogen
Atheroprotective effects of estrogen therpay seem to be related to what factor?
Age at which therapy is initiated –> younger postmenopausal woman are more protected
What is a major risk factor for atherosclerosis even in the absence of other factors and is sufficient to initiate lesion development?
Hypercholesterolemia
What are 2 activities which raise HDL levels?
- Exercise
- Moderate consumption of ethanol
Which disease causes a 100x ↑ risk for atherosclerosis-induced gangrene of LE’s?
Diabetes mellitus
Which circulating marker of inflammation associated wth ischemic heart disease is one of the easiest to measure and one of the most sensitive?
CRP
Expression of CRP is increased by a number of inflammatory mediators, especially what?
IL-6
What is a useful serum marker to gauge the effects of risk reduction measures, such as smoking cessation, weight loss, exercise, and statins?
CRP