L4 Atheroma and Aneurysms Flashcards
_______________: hardening of the arteries’
- Arterial wall thickening and __________
- Ageing phenomenon
- Mainly ____________
Arteriosclerosis: hardening of the arteries’
- Arterial wall thickening and loss of elasticity
- Ageing phenomenon
- Mainly small arteries/arterioles
_______________: ‘Degenerative disease of large and medium-sized arteries’
- Arteries only (>2mm diameter)
- Characterized by ____________ that protrude into vascular lumina leading to________ → ___________→_____________?
- Incidence increases w/ age
Atherosclerosis (ATHEROMA):‘Degenerative disease of large and medium-sized arteries’
- Arteries only (>2mm diameter)
- Characterized by intimal lesions (atheroma) that protrude into vascular lumina =>Lipid accumulation => fibrosis of vessel wall => fibrous cap formation
- Incidence increases w/ age
What is responsible for more morbidly and mortality in the western world than any other disease?
Atherosclerosis
What is a marker of reverse cholesterol transport and representative of reduced risk of atherosclerosis
HDL
What equation is used to calculate risk of Atherosclerosis?
Framingham Equations
Modifiable risk factors for Atheroma?
Modifiable
DYSLIPIDAEMIA
HIGH BLOOD PRESSURE
DYSGLYCAEMIA
CIGARETTE SMOKING
NON- Modifiable risk factors for Atheroma?
Non-Modifiable:
AGE
GENDER (Male, Post-Menopausal Female)
GENETICS
Familial Hypercholesteeremia
Lipoprotein Abnormalities
(Cascade Screening: one person positive test siblinds and children)
Distribution of Atheroma
- Abdominal Aorta
- Coronary Arteries
- Ilio-Fem-Popelitial
- Carotids
- Circle of Willis
Response to Injury Hypothesis?
Response to Injury Hypothesis:Chronic inflammatory healing response of arterial wall to endothelial injury
Spatial Heterogeneity (focal)- Occurs in specific spots along artery
Systemic - simultaneous involvement of multiple arteries
What is the earliest sign of Endothelial Damage possibly leading to Atheroma
REDUCED NITRIC OXIDE (NO) IS THE EARLIEST SIGN OF ENDOTHELIAL DAMAGE
What role do statins play for Atheromas?
STATINS INCREASE FIBROUS CAP TO STABILIZE ATHEROMA
Steps of Atheroma Formation (5)
- ENDOTHELIAL INJURY/LOSS
- Endothelial Dysfunction
- Macrophage Activation/Smooth Muscle Recruitment
- Macrophages/SMCs engulf Lipid
- Smooth muscle proliferation, Collagen Deposition, Extracellular lipid debris accumulate
Effects of Endothelial Injury ON the Vessel wall?
- ADHESION & MIGRATION
Enhanced expression of cellular adhesion molecules on endothelium- monocytes in blood adhere and enter wall
- Increased thrombogenicity w/platelet adhesion
- Increased LDL permeability – LDLs enter
Effects of Endothelial injury IN the Vessel wall?
- Growth factors (PDGF) secreted by platelets, endothelium, macrophages, smooth muscle cells.
- Myo-intimal cells proliferate
- Macrophages** (from blood) and **Smooth muscle cells (from media) migrate into the intima
- Smooth muscle cells in intima synthesize extracellular matrix including collagen
After Endothelial damage Macrophages engulf lipids => ____________
Extracellular lipid accumulates
_________accumulate => cause further damage
Macrophages engulf lipid => form foam cells
Extracellular lipid accumulates
Oxidized lipids accumulate => cause further damage
Activated MACROPHAGES:
- ________________
- Produce
a) ____________________
b) _____________________
c) _____________________
Activated MACROPHAGES:
- Recruit more macrophages
- Produce
a) Oxygen-Free Radicals => aggravate lipid oxidation
b) Growth factors
c) Factors which induce death of Vascular Smooth Muscle Cells
_____________ (neovascularisation) facilitates:
________________
________________
________________
ANGIOGENESIS (neovascularisation) facilitates:
- Lesion expansion
- Monocyte trafficking
- Hemorrhage into plaque
VASCULAR SMOOTH MUSCLE CELLS:
- Synthesize ______________
- Secrete ________________
VASCULAR SMOOTH MUSCLE CELLS
- Synthesize collagen => fibrous cap is formed
- Secrete Bone Morphometric Protein => CALCIUM deposition
The core of atheromas is composed of ______, _______, _________
The core of atheromas is composed of CHOLESTEROL, NECROTIC DEBRIS, FOAM CELLS ( oxidised LDL from macrophages)
Consequences of Atheroma? (5)
Atherosclerotic stenosis (narrowing)
Critical stenosis in coronaries: >70 % occlusion (angina or chronic IHD)
Mesenteric: ischemic bowel
Ischemic encephalopathy (Circle of Willis: Supplies blood to brain)
Intermittent claudication (Pain w/ walking)
Acute Plaque Change
Plaque rupture => thrombosis => infarction
Hemorrhage into the plaque (sudden expansion)
Thrombosis
– Occlusion
– Growth of the plaque
– Embolus from the thrombus
Vasoconstriction
– Many local factors
Vascular Ectasia (dilation)
– due to structural weaknesses
– aneurysms
Main Diseases associated with Atheroma?
Main Diseases associated with Atheroma
- ISCHAEMIC HEART DISEASE – coronary occlusion
- STROKES - cerebral / Circle of Willis occlusion
- PERIPHERAL VASCULAR DISEASE - ilio/femoro/popliteal occlusion
- ABDOMINAL AORTIC ANEURYSM – aorta -dilatation
___________: LOCALISED PERMANENT ABNORMAL DILATATION OF A BLOOD VESSEL (or HEART)
CAUSED BY WEAKNESS OF _________
Aneurysms: LOCALISED PERMANENT ABNORMAL DILATATION OF A BLOOD VESSEL (or HEART)
CAUSED BY WEAKNESS OF THE MEDIA
False vs. True Aneurysm vs. Dissection?
True Aneurysm – bounded by all arterial wall components (or wall of the heart) (ie intact but attenuated wall)
False Aneurysm (pseudoaneurysm) – breach in the vascular wall → extravascular hematoma that freely communicates with the intravascular space
Diseection -Tear in Inima, no Hematoma
Shapes of Aneurysm?
Berry Aneurysms are _________
Berry Aneurysms are Saccular
Consequences of Aneurysm?
Consequences of Aneurism:
- None
- Pressure on adjacent structures
- Occlusion by thrombus
- Rupture with hemorrhage into tissue / space
