Path slide set 1 Flashcards
what causes a thoracic aortic aneurysm?
HTN
young women, renal artery, beads on string
Fibromuscular dysplasia
occurs when blood enter defect in intima and travels through tissue plane within layers of aortic media
Aortic dissection
What is the most frequent preexisting histologically detectable lesion of an aortic dissection?
cystic medial degeneration. inflammation generally absent
Where are most dissections?
Ascending aorta
what causes and abdominal aorta aneurysm
atherosclerosis
HTN has increased prevalence in who?
advancing age and african americans
What is the cause of most HTN?
idiopathic (essential HTN; 90-95%
vascular morphological changes of HTN?
hyaline or hyperplastic arteriolosclerosis
In the pathogenesis of an Aneurysm, what weakens the vascular wall by ischemia of inner media?
Atherosclerosis
prolonged activation of endothelium may lead to endothelial dysfunction, often characterized by what?
- procoagulation
- proinflammation
- smooth muscle stimulation
In tact but thinned muscular wall at site of dilation
“true” aneurysm
what can an AAA impinge?
ureter or erosion of vertebrae
Other non major modifiable risk factors
- inflammation (levels of C-reactive protein)
- hyperhomocystinemia (>100umol/L)
- metobolic syndrome
major modifiable risk factors of atherosclerosis
- hyperlipidemia (LDL) based on diet and exercise
- HTN
- Smoking
- DM
Most common locations for atherosclerotic lesions in decreasing frequency?
- abdominal aorta
- coronary arteries
- popliteal arteries
- Internal carotid arteries
- Circle of Willis
Activated state of endothelium is characterized by expression of what?
- adhesion molecules
- procoagulants and anticoagulants
- voasoactive factors, growth factors
Constitutional risk factors for atherosclerosis
- Family history
- Age
- gender
Congenital conditions predisposing to aneurysm
- Marfan syndrome - fibrillin
- Ehlers Danlos - type 3 collagen
- Loeys-Dietz - TGF beta receptor - synthesis of elastin and COL 1 and 3
explain the gender predisposition for atherosclerosis
Males more than females until women hit menopause then increases and they eventually pass men
Advanced glycation end products can cause activation of endothelium due to what disorder?
uncontrolled diabetes
besides HTN, when else would you see hyaline arteriolosclerosis?
long standing diabetes
in the pathogenesis of an aneurysm, loss of vascular wall elastic tissue or ineffective elastin synthesis leads to what?
cystic medial degeneration
describe cystic medial degeneration
disrupted and disorganized elastin filaments and increased ground substance (proteoglycans)
what gives a “pulsating hematoma”
False aneurysm
defect though wall of vessel or heart, communicating with an extravascular hematoma?
“false” aneurysm
severe chest pain, radiating to back b/t scapulae
Aortic dissection
When oxidized LDL accumulated within macrophages and smooth muscle cells it forms what?
foam cells and a “fatty streak”
Clinically significant effects of large or multiple arteriovenous fistulas?
shunting of blood from arterial to venous and forcing heart to pump additional volume –> high-output cardiac failure
Describe Hyaline arteriolosclerosis
- increase smooth muscle matrix synthesis
- plasma protein leakage across damaged endothelium
- homogeneous pink thickening of vessel wall with luminal narrowing
complications of atherosclerotic plaques
- Rupture and ulceration
- hemorrhage
- embolism
- Aneurysm
what congenital vascular disorder are berry aneurysms associated with?
Autosomal dominant polycystic kidney disease
primary risk factor for aortic dissection
HTN
Accumulation of cholesterol crystals within macrophages is recognized by what? leading to what?
inflammasome, leading to IL-1 secretion and further macrophage and T cell recruitment and activation
explain intimal thickening
-smooth muscle cells from media go to intima where they proliferate and elaborate ECM
what is the more frequent epidemiology for an AAA
smoking men in their 50s
descibe hyperplastic arteriolosclerosis
- occurs in severe HTN
- smooth muscle cells form concentric lamellations (“onion skinning”) with resultant luminal narrowing
Describe the Response to injury model for pathogenesis of atherosclerosis
1: chronic endothelial “injury”
2: endothelial dysfunction, monocyte adhesion and emigration
3: macrophage activation and smooth muscle recruitment
4: macrophages and smooth muscle cells engulf lipid, forming “foam cells”
5: smooth muscle proliferation, collagen and other ECM deposition, extracellular lipid
HTN is what blood pressure?
> 140/90
clinical sign of AAA
pulsating mass in abdomen
epidemiology of aortic dissection
- hypertensive males 40-60
- marfans
Tertiary Syphilis affects what location?
Vaso vasorum of thoracic Aorta leading to ischemia of outer media
Focal thickening of INTIMA and MEDIA of medium to large muscular arteries resulting in stenosis
fibromuscular dysplasia
What is the stereotypical response to vascular injury?
intimal thickening
Loss of endothelial cells secondary to tissue damage or prolonged endothelial dysfunction leads to what?
vascular injury
Where is ACE found?
endothelial cells everywhere but especially in lungs
In the pathogenesis of an Aneurysm, what weakens the vascular wall by ischemia of outer media?
HTN and Tertiary syphilis
Clinical presentation of Thoracic Aortic aneurysm?
impingement of lower respiratory tree, esophagus, and recurrent laryngeal nerves - respiratory difficulty, difficulty swallowing and persistent cough
