Artherosclerosis

Question 1

Artherosclerosis

Answer 1

a disease progress triggered by subtle physical or chemical insults to endothelial cells lining the arteries

Question 2

Causes of enodthelial damage

Answer 2

1. Turbulent blood flow
2. Hypertension
3. Circulation of oxygen free radicals from smoking
4. Hyperlipidemia - high LDL levels
5. Raised blood sugar - diabetes

Question 3

Endothelial function

Answer 3

1. Regulate vasodilation - release of NO/Prostocyclin
2. Regulate vasoconstriction - endothelin/angiotensin II
3. Protect vessel wall

Question 4

pathophysiology of atheroscleroiss

Answer 4

1. Breakdown of endothelin
   • LDL deposits to accumulate within endothelial wall
2. Monocytes + Macrophages follow LDL
   • ingest to clear LDL
   • Over ingestion leads to foam cells forming which are dead macrophages add to deposit
3. Thus fatty streaks form
   • throgenic streak as platelets can adhere and form a clot
4. Fibrous cap forms
   • platelets gather and release platelet derived growth factor
   • stimulates smooth muscle growth
   • smooth muscle in turn secretes collagen, proteoglycan, eslastin
   -> FIBROUS CAP FORMS
5. Fibrous cap + Fatty streak = Plaque

Question 5

Atherosclerosis and calcium deposits

Answer 5

• Presence of fatty streaks causes smooth muscle underlying it to continue calcium depositing
• Calcium normally deposited by LDL
• HDL cannot remove calcium due to plaque
• Deposits stiffen artery walls

Question 6

3 major impacts of atherosclerosis

Answer 6

1. Aneurysm and rupture
   • weakened vessel wall can lead to aneurysm forming
   • aneurysm ruptures and lead to blood loss
2. Occlusion by thrombus
   • fibrous cap splits
   •Fatty streak exposed to platelets and platelet adhesion results
   -> thrombosis/embolism forms
3. Critical stenosis
   • slow progression
   • slow build up of plaque causes whole artery to become occluded

Question 7

Risk factors for atheroslcerosis

Answer 7

1. Hypercholesterolaemia
2. Male sex/post menopause female
3. Family history
4. Smoking
5. Diabetes

Question 8

Clinical features of atherosclerosis

Answer 8

-Heart
• Angina/MI

-Brain
• Internal carotid/ Middle carotid - stroke or cerebral atrophy

• Kidneys
  • Loss of blood supply causes blood pressure to be low
  • RAAS activated -> hypertension

-Popliteal occlusion
Claudication - cramping of leg induced by exercise
Peripheral ischaemia and Gangrene