Atherosclerosis

Question 1

What are the aetiologies of atherosclerosis?

Answer 1

Smoking
Hypertension
Hyperlipidaemia
Diabetes
Ageing
Sex
Genetics
High homocysteine levels

Question 2

How does hypertension increase risk of vascular disease?

Answer 2

High blood pressure can damage endothelium and increases turbulence

Question 3

How can diabetes lead to atherosclerosis?

Answer 3

It increases cholesterol levels and causes Advanced Glycation End products (AGE)
This causes abnormal cross linkage in vessel walls, increasing the risk of cholesterol trapping and causing firmer blood vessels

Question 4

At what age can fatty streaks begin to form in blood vessel endothelia?

Answer 4

Around 10 years old

Question 5

What are some examples of growth factors that allow for smooth muscle migration in vascular disease?

Answer 5

PDGF - Platelet Derived Growth Factor
FGF - Fibroblast Growth Factor
TGFα - Tissue Growth Factor alpha

Question 6

What is meant by stenosis?

Answer 6

Narrowing

Question 7

What are the 3 stages of atheroma progression?

Answer 7

Fatty streak
Fibrofatty plaque
Complicated plaque (With overlying thrombus)

Question 8

What are some examples of complication of arterial stenosis?

Answer 8

Coronary artery - Myocardial infarction
Carotid artery - Stroke, vascular dementia
Renal artery - Hypertension, renal failure
Peripheral artery - Claudication, ischaemia

Question 9

What is meant by ischaemia?

Answer 9

Lack of blood supply, leading to hypoxia, leading to damage

Question 10

What are some complications of vascular disease?

Answer 10

Stenosis
Aneurysm
Dissection
Thrombosis
Embolism

Question 11

What is meant by an aneurysm?

Answer 11

A site of abnormal and persistent dilation of an artery due to weakness in its wall

Question 12

What are some common types of aneurysm?

Answer 12

Mycotic
Atherosclerotic
Dissecting
Arteriovenous
Traumatic
Syphilitic

Question 13

Where is the most common site of aneurysm?

Answer 13

Abdominal aorta
AAA = Abdominal Aortic Aneurysm

Question 14

What are some complications of aneurysm?

Answer 14

Rupture (Most likely above 6cm)
Thrombosis
Embolism
Pressure erosion of adjacent structures (Most common in syphilitic aneurysm)

Question 15

What is an arterial dissection?

Answer 15

Splitting within the tunica media by flowing blood
Blood from the lumen can pass into a new path in the blood vessel wall
This leads to a false lumen which can allow pressure to build in the wall

Question 16

What are some common risk factors of arterial dissection?

Answer 16

Atheroma
Hypertension
Trauma
Coarctation
Marfan’s Syndrome - Leads to aortic abnormality
Pregnancy

Question 17

How does hypoxia cause injury and cell death?

Answer 17

No Oxygen = No ATP
This stops function of the Na+/K+ pump and the Ca2+ pump
Increased K+ causes swelling
Increased Ca2+ Stimulates:
ATPase = ATP Breakdown
Phopspholipase = Phospholipid breakdown
Endonucleases = Cytoskeleton breakdown
Mitochondrial permeability = Cytochrome C release so intrinsic apoptosis

Question 18

What changes can be seen within the first 20 minutes of a myocardial infarction?

Answer 18

There is no microscopic changes but there are some changes to the persons ECG

Question 19

What occurs after 20 minutes of a myocardial infarction?

Answer 19

Cells begin to die
Hypoxic injury begins to occur causing apoptosis and necrosis
The cells swell at first due to K+ build up, but they then undergo pyknosis and begin to shrink
The cells become red and the nucleus shrinks
Marginal contractions bands appear

Question 20

What is meant by a tamponade?

Answer 20

A build up of fluid in the pericardium

Question 21

What is hyperaemia?

Answer 21

A build up of blood

Question 22

At what stage after a myocardial infarction does full scarring occur?

Answer 22

After 6 weeks

Question 23

What cells cause scarring after a myocardial infarction?

Answer 23

Fibroblasts begin to fill holes in tissue
Fibroblasts lay down collagen fibres