Atherosclerosis

Question 1

Atherosclerosis is one type (the most common type) of what condition?

Answer 1

Arteriosclerosis

Question 2

What is the effect of the accumulation of atherosclerotic plaque to the vessel lumen size?

Answer 2

The lumen decreases due to the accumulation of plaque along the arterial wall

Question 3

What are the two main immune cells involved in atherosclerosis?

Answer 3

Macrophages and T cells

Question 4

Atherosclerosis directly involves the accumulation of _____ (HDL/LDL).

Answer 4

LDL - low density lipoprotein. This steamed the bad cholesterol because it directly involved in the progression of atherosclerosis.

Question 5

Identitfy 3 CVS conditions associated with atherosclerotic plaque accumulation.

Answer 5

Myocardial infarction
Stroke
Peripheral vascular disease

Question 6

What are the 3 histological layers of an artery?

Answer 6

The tunica intima, media and adventitia

Question 7

Which of the 3 layers of the arterial wall is most deep (close to the lumen)?

Answer 7

The tunica intima

Question 8

Which of the 3 layers of the arterial wall is most superficial (furthest from the lumen)?

Answer 8

The tunica adventitia

Question 9

The tunica intima is primarily composed of which tissue?

Answer 9

A single layer of endothelial cells.

It has a basement membrane which is the anchoring point for the endothelial cells.

Question 10

The tunica adventitia is primarily composed of tissue(s)?

Answer 10

Connective tissue
Vasa vasorum (blood supply to the artery wall)
Nervous fibers

Question 11

The tunica media is primarily composed of tissue(s)?

Answer 11

Smooth muscle

Elastin (allows the vessels to stretch to accomodate for increased blood volume).

Question 12

What are the two types of arteries?

Answer 12

Elastic and muscular

Question 13

What is the characteristic feature of elastic arteries?

Answer 13

They contain a high amount of elastin in the tunica media layer of the artery.

Question 14

What is the functional use of elastic arteries?

Answer 14

The are able to stretch a lot - facilitates expansion during systole and contraction during diastole.

Question 15

Give 3 examples of elastic arteries.

Answer 15

The aorta, carotid artery and iliac arteries.

Question 16

What is the characteristic feature of muscular arteries?

Answer 16

A layer of smooth muscle in the tunica media of these arteries.

Question 17

What is the functional use of muscular arteries?

Answer 17

Allows for vasoconstriction and vasodilation to modify blood flow.

Question 18

What is the smallest muscular artery?

Answer 18

The arterioles are the smallest muscular arteries - they also have the highest resistance to flow.

Question 19

Describe the basic pathophysiology of atherosclerotic plaque development.

Answer 19

The LDL floating the blood stream is oxidised by free radicals.
The oxidised LDL is taken up by macrophages which are unable to degrade the lipids and eventually become foam cells.
Foam cells and lipids buildup in the tunica intima forming atherosclerotic plaque.

Question 20

Why is atherosclerosis termed a “chronic inflammatory process”?

Answer 20

The oxidised LDL is damaging to the smooth muscle cells and endothelium -which draws macrophages to the area. The macrophages can also release cytokines which attract T cells.

Question 21

How can smooth muscle cell proliferation drive atherosclerotic plaque development?

Answer 21

Smooth muscle cell proliferation is driven by PDGF (platelet derived growth factor). The smooth muscle secrete extracellular matrix which is a component of atherosclerotic plaque.

Question 22

Outline the two main phases of atherosclerotic plaque development.

Answer 22

1. Fatty streak - the fatty streak is comprised of macrophages and LDL
2. atherosclerotic plaque - the tunica intima thickens due to the accumulation of lipids - which form patchily along the vessel wall.

Question 23

List (in order) the five most common locations for atherosclerotic plaque development.

Answer 23

1. abdominal aorta
2. coronary arteries
3. popliteal arteries
4. internal carotid arteries
5. circle of willis

Question 24

A atherosclerotic plaque rupture can be fatal due to what reason?

Answer 24

The rupturing of the plaque can expose thrombogenic fibres (pro-clotting fibres) which can lead to the development of a clot which can occlude the blood vessel.

Question 25

Outline the consequences of a haemorrhage into plaque.

Answer 25

The rupture of plaque can be contained within a lesion. which causes the lesion to expand rapidly - leading to vessel occlusion

Question 26

Outline the consequences of an aneurysm

Answer 26

Lesions can damage the tunica intima of the arterial wall leading to aneurysm (or ballooning of the arterial wall).

Question 27

What is an infarction?

Answer 27

An infarction is tissue death as a result of ischemia (or lack of oxygen).

Question 28

What are the two types of ischemia?

Answer 28

White and red infarction

Question 29

What is a white infarction?

Answer 29

Total or complete occlusion of the blood vessel preventing blood to the distal healthy tissue - the ischemic tissue becomes white.

Question 30

Where are common places for white ischemia to occur?

Answer 30

Solid organs like the heart, kidneys, and spleen

Question 31

What is a red infarction?

Answer 31

Partial occlusion of the blood vessel preventing all blood from supplying the distal healthy tissue - the ischemic tissue appears red.