Cardion L20 22 Atherosclerosis

Question 1

Atherosclerosis Definition

Answer 1

A disease of the arterial intima in which there is an accumulation of lipid debris with an associated inflammatory reaction.

There is focal asymmetric narrowing of vessels as the result of the build up of intimal athermanous plaque.

The process develops very slowly, over a period of 30-40 years, with progressive occlusion of the arterial vessels.

Question 2

Tunica media

Answer 2

External elastic membrane

Smooth muscle

Question 3

Tunica media

Answer 3

Internal elastic membrane
Lamina propria (smooth muscle and connective tissue)

Question 4

Arteriosclerosis definition

Answer 4

Arteriosclerosis describes the inevitable thickening of arterial walls with aging. This occurs in all populations and is not in itself pathological.

Question 5

Arteriosclerosis leading to pathological states.

Answer 5

Hypertension, as a result of reduction in the luminal diameter of the vessels and thus reduction of the internal volume of the circulation.

Ischemia, as a result of progressive reduction in blood flow.

Question 6

Atherosclerosis pathological lesions:

Answer 6

Fatty Streak
Fibrous Plaque
Complicated Fibrous plaque

Question 7

Fatty Streaks

Answer 7

Collection of lipid laden macrophages lying in the intima of the vessel.

Question 8

There is no what in fatty streaks

Answer 8

Free fat or evidence of an inflammatory reaction.

Question 9

Lesions found from

Answer 9

Infancy in the aortic intima and their presence is not related to nutritional status.

Question 10

Fibrous Plaque: Definition

Answer 10

The essential lesion of atherosclerosis. It is a nodular thickening of the arterial intima

Question 11

Fibrous Plaque: Composed of

Answer 11

A core of free fat (85% cholesterol and cholesterol ester; 15% triglyceride).

Proliferated mesenchymal cells (smooth muscle cells and macrophages)

Question 12

Fibrous Plaque: Defining factor

Answer 12

An area of fibrous scar at the base of the plaque

Abundant intercellular matrix (Proteoglycan)

Question 13

Fibrous Plaque: Complications of fibrous plaque:

Answer 13

Surface thrombosis

Intraplaque haemorrhage

Question 14

Fibrous Plaque: Surface thrombosis

Answer 14

Loss of surface endothelium leading to thrombosis. This may be a source of embolus or, alternatively, the thrombotic material may be incorporated into the plaque an thus increase its size.

Question 15

Fibrous Plaque: Intraplaque haemorrhage

Answer 15

Intraplaque haemorrhage may cause sudden increase in size of the plaque. Such haemorrhage arises from rupture of new vessels in the base of the plaque which originates in the inflammatory response to the free fat of the plaque.

Question 16

3. Four major sites: of atheroma

Answer 16

a. Carotid arteries → bifurcation
b. Coronary arteries → origin
c. Abdominal aorta → renal arteries and bifurcation
d. Deep femoral arteries → entering deep soft tissue

Question 17

atheroma description

Answer 17

1. Atheromatous lesions do not form uniformly throughout the circulation.
2. Disease is focal and lesions are located at specific sites.

Question 18

Endothelial Injury: causes

Answer 18

1. Cholesterol
2. Inflammatory mediators
3. Smoking
4. Infection
5. Toxins – endotoxins
6. Mechanical stress
7. Neoplasia

Question 19

Atheroma conseqeunces

Answer 19

Gradual Vascular Occlusion
Sudden Vascular occlusion
Haemorrhage

Question 20

Gradual Vascular Occlusion

Answer 20

Cerebral Ischaemia
Myocardial Ischaemia
Renal Ischaemia
Peripheral (limb) Ischemia

Question 21

Sudden Vascular occlusion

Answer 21

Thrombosis
Embolism

Myocardial infarction
Cerebral Infarction
Renal infarction

Question 22

Haemorrhage

Answer 22

Rupture of Aortic Aneurysm

Rupture of cerebral aneurysm

Question 23

Gradual Vascular Occlusion:

Answer 23

Cerebral ischemia
Cardiac ischemia
Renal ischemia
Peripheral (limb) ischemia

Question 24

Cerebral ischemia

Answer 24

Chronic ischemia damage leading to progressive cerebral atrophy and dementia.

Question 25

Cardiac ischemia

Answer 25

Reduction in coronary artery perfusion leads to a syndrome of pain (angina pectoris) with increase cardiac output i.e. exercise

Question 26

Renal ischemia

Answer 26

Reduction in renal blood flow will compromise renal function (reduced glomerular filtration) and will cause hypertension.

Question 27

Peripheral (limb) ischemia

Answer 27

Reduction of peripheral perfusion leads to pain on exercise (intermittent claudication) and eventually peripheral gangrene

Question 28

Sudden vascular occlusion → caused by

Answer 28

thrombosis or embolism causing acute ischemia and infarction

Question 29

Acute Haemorrhage: over a long period

Answer 29

→ atheromatous plaques leads to atrophy of the medial tissues and weakness of the wall.

Question 30

Acute Haemorrhage:

Answer 30

1. Catastrophic haemorrhage in atheromatous disease is the result of rupture of an aneurysm.
2. An aneurysm is a pathologically dilated vessel. There are a large number of causes of aneurysm of which one is atheroma.