Chap 5 + 6 Atherosclerosis & Intimal Hyperplasia

Question 1

What component sod the vessel wall contribute to atherosclerosis?

Answer 1

endothelium
subendothelium
SMC
Vaso Vasorum

Question 2

Name products secreted by the endothelium.

Answer 2

NO
Prostaglandins
Endothelin
AII

Question 3

Describe the formation of an athersclerotic plaque.

Answer 3

1. LDL migrates into subendothelium
2. LDL becomes oxidize
   This is one of the chemoattractants of monocytes to the site
3. Inflamm response to LDL and the oxidized LDL itself causes monocyte binding to ahteroma.
4. Monocytes migrate into sub endothelium, become MAC, take up oxidize LDL and become foam cells.
5. SMC and connective tissue form fibrous cap with a core of cholesterol esters, free cholesterol all forming the fibrous plaque.
6. fibrous plaque can become complicated by calcification, ulceration, hemorrhage, necrosis.

Question 4

How does the faso vasorum contribute to athersclerosis development?

Answer 4

Increase in VV with plaque formation

Increase leukocyte traffic and promote inflamm process

Question 5

What are the hypothesis of at hero devel.

Answer 5

lipid hypothesis
response to injury hypothesis
Monoclonal hypothesis

Question 6

Describe the process of intimal hyperplasia.

Answer 6

1. biochemical/mechanical insult leads to activation of SMC. They switch from contractile/quiescent to synthetic/proliferative.
2. Inflam cells migrate and release proteases (MMPs). these break down extracellular matrix.
3. SMC then liberated and migrate to intima where the proliferate and deposit matrix proteins.
4. SMC in intima cannot organize cellular and matrix components so histologically disordered.
5. De novo intimal layer accumulates over time.

Question 7

What are causes of lumen loss after vascular procedures.

Answer 7

Intimal hyperplasia

Wall remodelling (arteries enlarge cross sectional area to accommodate athero lesion, but can get wall shrinkage)

Vascular tone and recoil (HTN can lead to permanent increased tone, balloon angio destroys wall integrity loosing recoil property)

Restenosis

Question 8

What are inciting factors for IH?

Answer 8

hemodynamic stress

immune insult

Genetic susceptibility

Question 9

List the cellular effectors of IH.

Answer 9

Endothelial cells
SMC
PLT and leukocytes
Progenitor cells

Question 10

List biochemical effectors of IH.

Answer 10

Inflammatory mediators (cytokines)
Growth and Migration Factors (VEGF, TGF)
Matrix Metabolism  (MMP)
Coagulation factors
RAS

Question 11

List factors that Macrophages secrete.

Answer 11

IL-1, IL-6, IL-8 IL-10, TNF-alpha, IFN-beta, PDGF