MOD S7 - Atheroma Flashcards Preview

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Flashcards in MOD S7 - Atheroma Deck (19):
0

Define atheroma

The accumulation of intracellular and extracellular lipid in the tunica intima and tunica media of large and medium sized arteries

1

Define atherosclerosis

The thickening and hardening of arterial walls as a result of atheroma

2

Define arteriosclerosis

The thickening and hardening of arterial and arteriolar walls, usually as a result of diabetes mellitus or hypertension

3

Describe the macroscopic appearance of an early atheroma

Fatty streak
Lipid deposits in the tunica intima
Yellow and slightly raised

4

Describe the macroscopic appearance of a developing atheroma

Simple plaque
Raised yellow/white
Irregular outline
Widely distributed
Enlarged and coalesced

5

Describe the microscopic appearance of a developing atheroma

Microscopic:
Proliferation of smooth muscle cells
Accumulation of foam cells
Extracellular lipid

7

Describe the microscopic appearance of a late-stage atheroma

Fibrosis
Necrosis
Cholesterol clefts
Cholesterol deposition in tissues (not plaque)
Inflammatory cells

8

Describe the macroscopic appearance of a late-stage atheroma

Later:
Complicated plaque
Thrombosis
Haemorrhage into plaque
Calcification
Aneurism formation

9

Describe the cellular events that take place in atheroma formation

Endothelial damage occurs
Platelets arrive
PDGF released (platelet derived growth factor)
Smooth muscle cells proliferate
Smooth muscle cells migrate and take lipid with them
Macrophages arrive and phagocytose the lipid, becoming foam cells

10

What could some effects of atherosclerosis be if it was in a coronary artery?

Ischaemic heart disease
Angina
Arrhythmias
Cardiac failure
MI
Sudden death

11

What could some effects of atherosclerosis be if it was in the brain?

Transient ischaemic attack (symptoms for <24h)
Cerebral infarction (aka stroke)
Multi infarct dementia

12

What could some effects of atherosclerosis be if it was in a mesenteric artery?

Ischaemic colitis
Malabsorption
Intestinal infarction
Aneurism formation due to high pressure, hardening and weakening

13

What could some effects of atherosclerosis be if it was in a peripheral artery?

Peripheral vascular disease
Intermittent claudication
Leriche syndrome
Ischaemic rest pain
Gangrene

14

What is intermittent claudication?

Pain on exertion of calf muscles
Due to blockage or narrowing of peripheral arteries causing pain and ischaemia
NB intermittent claudication in the iliac artery causes gluteal pain

15

What are some risk factors for atheroma?

Age
Gender
Hyperlipidaemia
Smoking
Hypertension
Diabetes mellitus
Alcohol
Infection
Lack of exercise
Obesity
Stress
Oral contraceptives

16

Why is gender a risk factor for atheroma?

Pre-menopausal women have some measure of resistance to atheroma
Thought to be hormone related
NB slightly conflicts with oral contraceptives

17

Briefly describe the unifying hypothesis of atherogenesis

Endothelial injury occurs
Platelets adhere to vessel walls
PDGF secreted
Smooth muscle cell proliferation and migration
Insudation of lipid
Uptake of lipid by SMCs and macrophages
Migration of monocytes into tunica intima
Foam cells secrete cytokines
Cytokines further stimulate SMCs and recruit immune cells

18

How may atheromas be prevented?

Stop smoking
Change diet (less fat)
Change lifestyle (more exercise)
Treat hypertension
Treat diabetes
Lipid-reducing drugs

19

What can increase susceptibility to CHD?

Genetics eg familial hypercholesterolaemia
Geographical location (less common in Mediterraneans)
Ethnicity (Asians are more prone to CHD)