Vascular Pathology 1 - Atherosclerosis, Aneurism, Dissection

Question 1

What is ischaemia?

Answer 1

Deficiency of blood in a tissue causing a shortage of oxygen and impaired aerobic respiration

Question 2

What is ischaemia due to?

Answer 2

increased demand for oxygen that is not met, local vascular narrowing or occlusion, systemic reduction in tissue perfusion

Question 3

What is hypoxia?

Answer 3

A deficiency of oxygen in tissues

Question 4

What is hypoxia due to?

Answer 4

Ischaemia, impaired respiratory function, decrease in oxygen carrying capacity of the blood

Question 5

What is an infarct?

Answer 5

An area of necrosis caused by acute ischaemia

Question 6

What is a thrombus?

Answer 6

A clotted mass of blood that forms within the cardiovascular system during life

Question 7

What is an embolus?

Answer 7

An intravascular solid, liquid or gaseous mass carried in the blood stream to a site remote from its origin

Question 8

What is atherosclerosis?

Answer 8

An accumulation of lipid and fibrous connective tissue in the intima of medium and large arteries

Question 9

What is the first step in the pathogenesis of atherosclerosis?

Answer 9

Chronic endothelial injury due to hyperlipidaemia, hypertension, smoking, hemodynamic factors, toxins, viruses, immune reactions

Question 10

What is the response to the chronic endothelial injury?

Answer 10

Endothelial dysfunction

Question 11

What happens in endothelial dysfunction?

Answer 11

Increased vascular permeability, platelet adhesion (by exposure of the subendothelial ECM), monocyte adhesion (by expression of selectins, VCAM-1 and ICAM-1), release of PDGF, decreased releasing factors to inhibit clotting, production of ROS, altered release of vasoactive substances

Question 12

What is the result of endothelial dysfunction?

Answer 12

LDLs can gain entry to the intima

Question 13

What happens to LDLs once they enter the intima?

Answer 13

They are oxidised by ROS

Question 14

What causes the recruitment of monocytes to the intima?

Answer 14

the leukocyte adhesion molecules on the endothelium (selectins, VCAM-1, ICAM-1) and the chemoattractant signals (IL-8, MCP-1)

Question 15

How are foam cells formed?

Answer 15

By the phagocytosis of LDL by macrophages

Question 16

Why do smooth muscle cells migrate from the media into the intima?

Answer 16

In response to the PDGF released from the endothelium and macrophages as well as FGF and TGF

Question 17

What do smooth muscle cells in the intima do?

Answer 17

Secrete ECM (mostly collagen) to wall off the lipid core of the plaque

Question 18

How is the lipid rich necrotic core of the plaque formed?

Answer 18

The break down of foam cells by apoptosis and the breakdown of collagen by matrix metalloproteinases

Question 19

What are the results of atherosclerosis?

Answer 19

vessel stenosis, impaired vasodilation, plaques vulnerable to rupture, local prothrombotic environment

Question 20

What are the risk factors for atherosclerosis?

Answer 20

• age
  
  • gender
  • family history
  • hypertension
  • diabetes mellitus
  • smoking
  • hypercholesterolaemia
  • obesity
  • physical inactivity
  • proteinuria
  • type A personality
  • infections

Question 21

Why is diabetes a risk factor for atherosclerosis?

Answer 21

Because hyperglycaemia causes oxidative stress and damages endothelium and patients have smaller denser LDL which is more atherogenic

Question 22

At what stage of atherosclerosis do you see fatty streaks?

Answer 22

When there are foamy macrophages present but before migration of smooth muscle cells

Question 23

What other features are seen histologically in atherosclerosis?

Answer 23

cholesterol clefts, calcification, lymphocytes

Question 24

What are the complications of atherosclerosis?

Answer 24

ischaemia (narrowing), infarction (athero-embolism or thrombo-embolism), aneurysm

Question 25

What is an aneurysm?

Answer 25

A localised abnormal dilation of a blood vessel or the heart

Question 26

What is a true aneurysm?

Answer 26

Where the dilation occurs but the wall is intact

Question 27

What is a false aneurysm?

Answer 27

Where there is a defect in the vascular wall so that blood can go in the intravascular space

Question 28

What is a dissection?

Answer 28

Blood between two layers of the vascular wall

Question 29

What is a fusiform dilation?

Answer 29

The dilation of the entire circumference

Question 30

What is a saccular dilation?

Answer 30

A focal dilation

Question 31

What are the causes of aneurysm?

Answer 31

atherosclerosis, congenital weakness in the wall, systemic hypertension, infection in an artery wall

Question 32

What are the complications of an aneurysm?

Answer 32

Rupture, narrowing

Question 33

What is Marfan syndrome?

Answer 33

A genetic abnormality in fibrin meaning that the elastin isn’t made right - can lead to an aneurysm

Question 34

What is arteriosclerosis?

Answer 34

Hardening of the arteries - includes atherosclerosis and age related changes

Question 35

What happens to elastic arteries with age?

Answer 35

Degeneration of elastic tissue and intimal fibrosis

Question 36

What is arteriolosclerosis?

Answer 36

Deposition of plasma proteins and collagen in the endothelium of small arteries and arterioles - arteriole wall becomes thickened with eosinophilic glassy material and the lumen is narrowed

Question 37

What are the consequences of arteriolosclerosis?

Answer 37

stroke due to rupture of weakened vessels, ischaemia/infartction in the retina or chronic ischaemia in the kidney