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Cardiovascular > Atherosclerosis > Flashcards

Flashcards in Atherosclerosis Deck (28):
1

What is atherosclerosis?

Hardness of arteries
Caused by fatty deposits on the inner walls of the arteries

2

Risk factors for atherosclerosis?

Age: the older you get the more fatty deposits

Tobacco smoking

High serum cholesterol

Obesity

Diabetes

Hypertension

Family history

3

Where are atherosclerotic plaques distributed?

Arteries! peripheral, coronary

4

What determines where atherosclerotic plaques develop?

Haemodynamic factors

Changes in flow / turbulence cause arteries to change their wall thicknesses and develop neointima

5

What is neointima?

Scar tissue that forms within vessel walls

6

How does hypertension cause atherosclerosis?

Higher pressure, more strain on vessel walls

7

How does smoking cause atherosclerosis?

Smoking causes injury to blood vessel walls, causing damage to endothelial cells which is the first step towards atherosclerosis

8

Describe the structure of an atherosclerotic plaque?

Lipids
Necrotic core
Connective tissue
Fibrous cap

9

What complications occur as a result of atherosclerosis?

The plaque can rupture causing thrombus

The plaque can get so big it occludes blood flow = ischaemia, infarction

10

How does obesity cause atherosclerosis?

Fat in the pericardium, that causes the release of proteins that cause inflammation

11

How does diabetes cause atherosclerosis?

High blood glucose = damage to endothelium, which is the 1st step towards atherosclerosis

12

Desrcibe the process of atherogenesis.

Injury to endothelial cells - endothelial dysfunction
(caused by smoking, virus, high blood sugar etc.)

Injury causes signals to be sent to circulating leukocytes which then accumulate at the area and cause atherosclerotic build up

13

What is ischaemia-reperfusion injury?

If a tissue is starved of blood and therefore oxygen, when the blood supply returns to the area it can cause damage

Inflammation and oxidative damage occurs because of the environment created when it was lacking in nutrients and oxygen

Neutrophils can enter the damaged area and can sometimes cause more damage

14

What's the difference between HDLs and LDLs?
What are they?

HDLs - high density lipoprotein
LDLs - low ""

They are proteins that transport cholesterol around the body

15

What do LDLs do?

Carry cholesterol from liver to cells

Bad, because they cause fatty deposits to build up in the wrong places, ie. endothelial cells

16

What do HDLs do?

Transport cholesterol from the cells to the liver

Good

17

List the 5 stages of atherosclerosis plaque progression.

1. Fatty streaks

2. Intermediate lesions

3. Fibrous plaques/advanced lesions

4. Plaque rupture

5. Plaque erosion

18

When do fatty streaks first start to appear?

At about age 10

19

What are fatty streaks made of?

Lipid laden macrophages
and T lymphocytes

20

Where are the fatty streaks?

In the intimal layer of the vessel wall

21

What do intermediate lesions consist of?

Lipid laden macrophages

Vascular smooth muscle cells

T lymphocytes

Adhesion of platelets to vessel wall

Isolated pools of extracellular lipid

22

Where are the intermediate lesions?

In the intimal layer of the vessel wall

23

What do the fibrous plaques consist of?

They are intermediate lesions but with a fibrous cap

Fibrous plaques are made of extracellular proteins (collagen, elastin) laid down by smooth muscle cells

The centre of the plaque starts to become necrotic

The plaque becomes calcified

24

At what stage does the plaque get a fibrous cap?

Stage 3: when they become fibrous plaques/advanced lesions

25

Plaques are constantly growing and receding. True or false?

True!

The fibrous cap has to be resorbed and re-deposited so it can be maintained

26

What makes the plaques rupture?

Inflammatory conditions
Increased enzyme activity

27

What happens when the plaque ruptures?

The fibrous cap comes off

Revealing the basement membrane, collagen, necrotic tissue

Causing vessels within the plaque to haemorrhage

This leads to a thrombus and vessel occlusion

28

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