Cardio

Question 1

Definition: Atherosclerosis

Answer 1

A disease of the arteries characterized by the deposition of fatty material on their inner walls

Question 2

Where is atherosclerosis found?

Answer 2

Within peripheral and coronary arteries

Question 3

What is involved in the structure of plaque?

Answer 3

Lipid, necrotic core, connective tissue, fibrous cap

Question 4

What are the 4 main cell types involved in atherogenesis?

Answer 4

1) Endothelium cells
2) Macrophages
3) Smooth muscle cells
4) Platelets

Question 5

What is the response to injury hypothesis in atherogenesis?

Answer 5

• Atherogenesis is initiated by an injury to the endothelial cells which leads to endothelial dysfunction
• Endothelial dysfunction leads to signals being sent to circulating leukocytes which then accumulate and migrate in vessel wall
• INFLAMMATION!

Question 6

Which two substances allow leukocyte ahdesion and migration into vessels once inflammation has been initiated?

Answer 6

• Selectins: control rolling along endothelium

- Chemoattractants: produce concentration gradient and send signals which allows leukocytes to migrate to site of injury

Question 7

Describe the stages of atherosclerosis progression

Answer 7

1: FATTY STREAKS - consists of aggregations of lipid-laden macrophages (foam cells) and T-lymphocytes within intimal layer
2: INTERMEDIATE LESIONS - consists of foam cells (release pro-inflammatory cytokines), vascular smooth muscle cells, T-lymphocytes, platelets aggregate and stick to vessel wall, isolated pools of extracellular lipid

3: FIBROUS PLAQUES OR ADVANCED LESIONS -
impedes blood flow, covered by fibrous cap made of ECM proteins (collagen, elastin), overlies lipid core and necrotic debris

4: PLAQUE RUPTURE - balance of plaque resorption an re-disposition is shifted due to increased enzyme activity, this degrades matrix and plaque ruptures. Haemorrhage of vessels and exposure of plaque contents; thrombus formation and vessel occlusion
5: PLAQUE EROSION - cap does not disrupt, luminal surface underneath clot may not have endothelium present but is rich with SMC

Question 8

How is coronary artery disease treated? What was once an issue but isn’t any more?

Answer 8

PCI- percutaneous coronary intervention

Restenosis used to be an issue but is no longer due to drug elution on stents (Taxol and sirolimus commonly used)