Cardiovascular Pathology

Question 1

what are some lifestyle choices that can cause atherosclerosis?

Answer 1

• smoking
• obesity
• lack of exercise
• diet

Question 2

what are some non-modifiable factors that may contribute to atherosclerosis?

Answer 2

• age
• gender
• genes

Question 3

what is high blood cholesterol known as?

Answer 3

hyperlipidaemia

Question 4

what is atherosclerosis?

Answer 4

a chronic inflammatory response followed by the healing response

Question 5

how is an atheroma formed?

Answer 5

• presence of cholesterol in the vessel walls initiates a chronic inflammatory response
• the healing response is triggered
• this causes formation of fibrous tissue

Question 6

what is vascular pathology?

Answer 6

either stenosis/obstruction or weakening of the vessel walls leading to dilation/rupture

Question 7

what genetic condition may make a patient more likely to develop atherosclerosis?

Answer 7

familial hypercholesterolaemia (mutation of LDL receptor gene)

Question 8

what is the normal state of an endothelial cell known as?

Answer 8

basal state

Question 9

what is the pathological state of an endothelial cell known as?

Answer 9

activated state

Question 10

explain the structure of basal state endothelial cells:

Answer 10

• surface is smooth & non-adhesive (inflammatory cells cannot attach and aggregate on the surface)
• non-thrombocytic (cannot induce activation of the coagulation system)

Question 11

explain the structure of an activated endothelial cell:

Answer 11

• surface of endothelial cell becomes changed because of cytokines, bacterial toxins, lipid products… inflammatory cells adhere to the surface of cells
• permeability changes and inflammatory cells can move in
• vasoactive substances are released causing vasoconstriction/vasodilation

Question 12

what are the two phases of a forming atheroma?

Answer 12

inflammation phase and healing phase

Question 13

what occurs during the chronic inflammation phase of atheroma formation?

Answer 13

• endothelial cells change surface cell receptors & become more permeable to lipids
• altered cell adhesion molecules so monocytes (macrophages and T cells) attach to endothelium & move into blood vessel wall
• macrophages are phagocytes and engulf the lipid present in the tunica intima

Question 14

what occurs when macrophages engulf lipids?

Answer 14

• enlarged size
• pale colour
• known as FOAM CELLS

Question 15

what occurs during the healing phase of a forming atheroma?

Answer 15

• proliferation of smooth muscle cells and fibrous tissue in the tunica intima
• macrophages produce IL-1 which activates T cells
• more cytokines & chemokines activate inflammatory cells
• fibrous tissue formation over the lipid & a fatty atheroma (plaque) is formed

Question 16

what are the resulting effects of atheroma formation?

Answer 16

• ischemia
• infarction
• thrombosis
• embolism

Question 17

what is ischemia?

Answer 17

decreased blood supply to tissue/organ

Question 18

what is infarction?

Answer 18

complete occlusion of a blood vessel leads to tissue necrosis

Question 19

what is thrombosis?

Answer 19

damage of endothelial cells or plaque rupture which causes triggering of the clotting cascade to form a thrombus on the plaque

Question 20

what is meant by embolism?

Answer 20

thrombus breaks off and travels in the blood stream

Question 21

how can chronic periodontitis lead to atheroma formation?

Answer 21

• inflammation and the biofilm will result in the presence of growth factors & cytokines in the circulation
• invitation of an acute phase response in the production of c-reactive protein by the liver

Question 22

what is peripheral vascular disease?

Answer 22

ischemia in the muscles of the lower legs

Question 23

what may occur due to peripheral vascular disease?

Answer 23

• claudication = pain and cramps
• gangrene = complete obstruction of the arteries leading to necrosis of muscles
• coagulation necrosis and infection due to anaerobic bacteria

Question 24

what is an aneurysm?

Answer 24

an abnormal dilation in the wall of a blood vessel

Question 25

what are the main causes of an aneurysm?

Answer 25

• developmental = inherited condition
• degenerative = infection with mycotic infections or syphilis
• traumatic = atherosclerosis

Question 26

what occurs in the vessel wall that leads to an aneurysm?

Answer 26

• macrophages (present due to inflammation) produce matrix metalloproteinases
• MMPs degraded the fibrous tissue leading to weakening of the blood vessel wall
• this leads to abnormal dilation and an increase in size

Question 27

what occurs during a myocardial infarction?

Answer 27

• myocytes switch to anaerobic respiration to supply energy to the muscles (ineffective)
• coagulation necrosis of myocardial muscle then occurs

Question 28

how does the cardiac tissue heal after a myocardial infarction?

Answer 28

by formation of granulation tissue

- impaired heart function

Question 29

what are tumours of the blood vessels?

Answer 29

• hamartomas

- kaposi sarcoma

Question 30

what are hamartomas?

Answer 30

• collection of cells that are normal but increased in size
• non-malignant
• no connective tissue capsule surrounding these structures (normally found in benign tumours)

Question 31

who is most likely to suffer from Kaposi Sarcomas?

Answer 31

patients with advanced HIV infection

Question 32

what is the aetiology of kaposi sarcomas?

Answer 32

Herpes virus 8

Question 33

what is a haemangioma?

Answer 33

hamartoma of the endothelial cells (commonly seen in head & neck)

Question 34

what are examples of benign cardiac tumours?

Answer 34

• myxoma

- lipoma

Question 35

what is an example of a malignant cardiac tumour?

Answer 35

angiosarcoma

Question 36

what can pathology of heart valves lead to?

Answer 36

• stenosis (failure of valve to open completely)
• insufficiency (failure of valve to close properly)
• vegetations (nodules on the endocardium & valve that may be thrombocytic or infective)

Question 37

what is the most common valve condition?

Answer 37

calcification aortic stenosis

Question 38

what occurs to a patient suffering from calcific aortic stenosis?

Answer 38

• dystrophic calcium deposits (result of chronic endothelial injury)
• narrowing of the valvular orifice which affects valve function

Question 39

what type of reactions are involved in rheumatic heart disease?

Answer 39

• type 2 (cytotoxic type of fibrous sensitivity reaction)

- type 4 (cell-mediated T cell reaction)