Pathology of Atherosclerosis Flashcards
What is Atherosclerosis
Atherosclerosis is a type of arteriosclerosis ,Hardening of the arteries
A condition in which plaque builds up inside the arteries.
What are the non-modifiable risk factors of atherosclerosis
Genetic abnormalities ,Family history, Increasing age, Male gender
What are the modifiable risk factors of atherosclerosis
Hyperlipidemia (esp. hypercholestrolemia), Hypertension, Cigarette smoking, Diabetes.
What is the pathogenesis of atheroscleriosis
Response to injury: chronic inflammatory and healing response of the arterial wall to endothelial injury.
What are the components of the plaque
- Fibrous cap
made up of collagen (produced by smooth muscle cells) - Necrotic core
made up of macrophages & fat - Inflammatory component
What happens if we have a strong fibrous cap
plaque will remain in place
What happens if we have a thin fibrous cap
it will break = thrombosis which will cause either
1. occulusion = MI
2. healing = narrowed lumen
How to identify the fibrous cap histologically
stains blue in H&E
Darker spots = dystrophic calcification
occurs in abnormal tissue such as advanced atherosclerosis (causes the BV to be hard)
Where are plaques more likely to occur
plaques usually happen at bifurcations bcuz of they’re areas with turbulent flow (smooth BF is disrupted);
if this area is already diseased with atherosclerosis this will be a prime area where the plaque will break and thrombosis can happen
What are 3 ways that a plaque can be distrubed
- Fissuring: crack which releases materials from the intima (fat) which is thrombogenic so it causes thrombosis
- Ulceration
- Bleeding into the plaque (by the vessels supplying the plaque, which are primitive vessels that can rupture easily)
Which plaques are more likely to rupture
contain large areas of foam cells and extracellular lipid
fibrous caps that are thin or contain few smooth muscle cells or have clusters of inflammatory
cells
What intrinsic factors can cause plaque rupture
- Fibrous cap remodelling
- Decreased SM cells (these produce collagen responsible for the cap integrity)
What extrinsic factors can cause plaque rupture
- Adrenergic stimulation (increase BP and stress)
- Stress, earthquake, waking in the morning.
What is the most common artery where atherosclerosis occurs
L. Ant. Descending artery
How can a plaque grow
- Plaque disruption = superficial platelet aggregation and thrombosis are common, repetitive, and often clinically silent complications
-Healing and resorption of their overlying thrombi results in the growth of atherosclerotic lesions.
What happened in these images
How can atherosclerosis progress
What clinical syndromes can occur as a result of atherosclerosis
- Coronary artery disease
- Angina pectoris
- Myocardial infarction
- Peripheral vascular disease
- Aneurysms
What is peripheral arterial/vascular disease
If the plaque affects the vessels of the lower limb, patient will experience claudications (pain), leg will appear pale (not enough blood is reaching it), loss of hair (more common in men), & reduced pulse
What can cause this
Ulceration Pallor
not enough blood reaching lower limb
= loss of fingers, part of the skin, sometimes even tendons of the fingers become visible
What are aneurysms
Damage to vascular wall(most common is aorta) lead to weakening if the wall and possibility of dilation/ rupture
Secondary to atherosclerosis
Pathophysiology of aneurysm
- atherosclerosis
- ulceration
- thrombosis
- vessel becomes weak & walls become thin
- blood wants to flow through
- BV dilates & becomes an aneurysm
- rupture can happen & the patient will die instantaneously
Most common location of an aneurysm
Abdominal aorta at the iliac biforcation
