Ch 11-Blood Vessels-Galbraith PDF's Flashcards
(99 cards)
This vascular anomaly is an artery –> vein connection, is most commonly a developmental defect, but may arise secondary to inflammation and trauma
AV fistula
An AV fistula may lead to: ___
Rupture and hemorrhage or to high-output cardiac failure
This vascular anomaly is a focal thickening of intima and media of medium to large muscular arteries, resulting in stenosis
Fibomuscular dysplasia
Looks like beads on a string. Think Renal a.
List some stimuli that may induce an activated state of endothelium in response to injury:
Turbulent blood flow HTN Complement, bacterial products, lipid products, glycation end products Viruses Hypoxia, acidosis
The stereotypical response to vascular injury is ___
Intimal thickening
- Smooth muscle cells from the media migrate to the intima, where they proliferate and elaborate ECM
- The intima is thus thickened, potentially affecting blood flow in that vessel
___ is seen in response to any injury to a vessel, regardless of cause
Vascular intimal thickening
What are some risk factors for essential HTN?
High Na intake Obesity Stress Smoking Physical inactivity
What are some humoral factors that cause peripheral constriction?
Ang II Catecholamines Thromboxane Leukotrienes Endothelin
What are some humoral factors that cause peripheral dilation?
PG’s
Kinins
NO
What are neural factors that cause peripheral constriction?
What are neural factors that cause peripheral dilation?
Constrictors=alpha adrenergic
Dilators=beta adrenergic
Blood volume and vascular tone is modified and maintained by the ___
RAAS
This morphologic change seen in HTN is characterized by an increased smooth muscle matrix synthesis, plasma protein leakage across damaged endothelium, and a homogenous pink thickening of the vessel wall with associated luminal narrowing
Hyaline arteriolosclerosis
Usually seen in smaller arterioles
This morphologic change seen in HTN occurs in severe HTN, the smooth muscle cells form concentric lamellations with resultant luminal narrowing
Hyperplastic arteriolosclerosis
Concentric lamellations=”ONION SKINNING”
What are some constitutional risk factors associated with atherosclerosis?
FH
age
Gender
What are some modifiable risk factors (major) associated with atherosclerosis?
Hyperlipidemia (especially LDL)
HTN
Smoking
DM
List the steps involved in the response to injury model of the pathogenesis of atherosclerosis:
1) Chronic endothelial injury —> 2) Endothelial dysfunction —> 3) Macrophage activation, smooth muscle recruitment —> 4) Macrophages and smooth muscle cells engulf lipid (foam cells) —> 5) smooth muscle proliferation, collagen and other ECM deposition, EC lipid (this stage has a fibrofatty atheroma with fibrous cap and lipid debris)
Where do most atherosclerotic lesions occur?
Tend to occur at openings of exiting vessels, branch points, POSTERIOR ABDOMINAL AORTA-due to flow disturbances normally seen in these locations
What are the lipids in atheromatous plaques predominantly made of?
Cholesterol and cholesterol esters: These accumulate in the intima, taken up by macrophages and partially oxidized.
When modified LDL (macrophages that take up lipids and partially oxidize them) further accumulates within macrophages and smooth muscle cells to form foam cells, a lesion develops known as ___
“Fatty streak” —> This stimulate an inflamm response to accumulation of this toxic form of LDL
Describe the composition of an atheromatous plaque that forms in the pathogenesis of atherosclerosis:
Fibrous cap: smooth muscle cells, macrophages, foam cells, lymphocytes, collagen, elastin, proteoglycans, neovascularization
Necrotic center: cell debris, cholesterol crystals, foam cells, calcium
List the common sites of involvement of atherosclerosis in descending order:
Abdominal aorta Coronary arteries Popliteal arteries Internal carotids Circle of willis
What are some complications of atherosclerotic plaques?
Rupture and ulceration –> may lead to thrombosis
Hemorrhage–> may follow plaque rupture
Embolism –> may follow plaque rupture
Aneurysm
As a consequence of atherosclerosis, the lumen of the affected vessel gradually shrinks (~70% occlusion), eventually leading to ischemia downstream. This is known as ___
Critical stenosis
May lead to chronic ischemia of myocardium, bowel, brain, the extremities, etc
Describe the lipid core and fibrous cap in a vulnerable atherosclerotic plaque
Vulnerable plaque has a large lipid core and thin fibrous cap which makes the plaque weaker
Conversely, a stable plaque will have a thick fibrous cap and smaller lipid core.
