Vascular disease: Atheroma and its complications

Question 1

What is arteriosclerosis

Answer 1

Thickening and hardening of the wall of an artery

Question 2

What is arteriolosclerosis

Answer 2

Thickening and hardening of the wall of an arteriole

Question 3

What is an atheroma

Answer 3

AN important disease of large and medium arteries

Question 4

What is atherosclerosis

Answer 4

Arteriosclerosis due to atheroma

Question 5

What is the most common cause of arteriosclerosis in large and medium arteries

Answer 5

Atheroma

Question 6

What is the most common cause of thickening and hardening of the walls of small arteries and arterioles

Answer 6

High blood pressure

Question 7

What are the three changes that occur in hypertensive arteriosclerosis

Answer 7

• HYpertropy of media
• FIbroelastic thickening of intima
• Elastic lamina reduplication

Question 8

In hypertensive arteriosclerosis, what are the wall structures replaced by

Answer 8

Amorphous hyaline material

Question 9

What is the consequence of a reduction of vessel lumen because of hypertensive vascular changes

Answer 9

Reduced flow which means there is ischaemia in supplied tissue

Question 10

What is the consequence of increased rigidity of vessel wall because of hypertensive vascular changes

Answer 10

Loss of elasticity and contractility. Means it is unresponsive to normal vessels; control agents like vasodilators

Question 11

Where does an atheroma occur in

Answer 11

High pressure systems

Question 12

Where does an atheroma not occur in

Answer 12

Venous system because it is not high pressure

Question 13

What is an atheroma initially a disease of

-What does it later affect

Answer 13

Tunica intima

-Tunica media

Question 14

What are the four recognisable stages of the development of an atheroma

Answer 14

• Fatty streak
• Lipid plaque
• Fibrolipid plaque
• Complicated atheroma

Question 15

Stages of development of an atheroma

Answer 15

1) Blood lipids enter intimate through damaged endothelium
2) Lipids are phagocytosed by macrophages in intimate to make raised fatty streak
3) Lipid plaque is released by macrophages
4) Macrophages secrete cytokines which stimulate my-fibroblasts to secrete collagen
5) Early damage to elastic lamina and media
6) COllagen cover plaque surface (fibrilipid plaque)
7) Media thins, with replacement of muscle fibres by collagen
8) Lipids in intimate become calcified
9) Surface of fibro-lipid plaque ulcerates
10) Thinning of media leads to weakness and inelasticity (complicated atheroma)

Question 16

What is the complication of an expansion of intima

Answer 16

Reduction in the size of the lumen so there is less blood flow and hence oxygenation of tissue

Question 17

What is the complication of an ulceration of atheromatous intima

Answer 17

Predisposition to thrombus formation

Vessel gets occluded

Question 18

what is the complication of replacement of muscle and elastic fibres in media

Answer 18

There is loss of elasticity so there is thinning and stretching (leads to an aneurysm)

Question 19

What does an atheroma in a leg artery cause

Answer 19

Intermittent claudication (pain when walking and exercising in calves, but is relieved by resting)

Question 20

What does an atheroma in the mesenteric arteries cause

Answer 20

Ischaemic colitis (inflammation of large intestine because of inadequate blood supply)

Question 21

How does damage to media lead to an aneurysm

Answer 21

• Enlarging intimal atheroma plaque leads to atrophy of the media
• MUScle and elastic fibres in media are replaced by collagen
• Collagen is strong but is neither contractile nor capable of elastic recoil
• Therefore with each systolic pulse, the wall of an artery stretches and thins, particularly when blood pressure is elevated

Question 22

What is an aneurysm

Answer 22

Abnormal permanent focal dilatation of an artery

Question 23

What is the most common type of aneurysm

Answer 23

In abdominal aorta

Question 24

Three type of aneurysms

Answer 24

• Saccular
• Fusiform
• Dissecting

Question 25

What is a mycotic aneurysm mostly caused by

Answer 25

Endocarditis (infection of heart valve)

Bacterial septicaemia

Infection of arterial wall

Weakening and dilatation is an aneurysm