Atheroma and thrombosis

Question 1

define atherosclerosis

Answer 1

degeneration of arterial wall characterised by fibrosis, lipid deposition and inflammation which limits blood circulation and predisposes to thrombosis.

Question 2

which vessels or positions on vessels are commonly affected by atherosclerosis.

Answer 2

Bi furcations (tubulent flow)
Abdominal aorta
Coronary arteries
Popliteal arteries vessels in the leg
Carotid vessels
Circle of willis.

Question 3

what are the common non modifiable risk factors of atheroscerlosis.

Answer 3

age, male, FH, genetics.

Question 4

what are the common modifiable risk factors of atheroscerlosis.

Answer 4

Hyperlipidaemia (LDL:HDL)
Hypertension
Smoking
Diabetes
Other: CRP, ↑homocysteine,(metabolic condition)?
Stress

Question 5

what causes the atherosclerotic process to begin

Answer 5

chronic injury and repair of the endothelium

First step is endothelial injury.

Question 6

what causes endothelial injury

Answer 6

Haemodynamic injury, chemicals, immune complex deposition, irradiation.

Question 7

In which layer of the artery does lipid deposit in hyperlipademia.

Answer 7

intima

Question 8

what factors are produced upon damage of the endothelium

Answer 8

adhesion factors.

Question 9

what cells migrate to the intima engulfing lipid and forming foam cells

Answer 9

monocytes

Question 10

what is the the name for the point at which monocytes engulf lipid and form foam cells

Answer 10

fatty streak.

Question 11

what do the foam cell secrete to circulate more macrophages, lymphocytes and smooth muscle cells.

Answer 11

chemokines

Question 12

what is the function of smooth muscle cells in the atherosclerotic plaque

Answer 12

proliferate and secrete connective tissue.

Question 13

what forms the fibrous cap of a atheroscleotic plaque

Answer 13

smooth muscle, macrophages, foam cells, lymphocytes, collagen, elastin and proteoglycans.

Question 14

what forms the necrotic centre of the atherosclerotic plaque

Answer 14

cell debris, cholesterol crystals, foam cells and calcium.

Question 15

what pathology follows atherosclerosis

Answer 15

occlusion
weakening of vessel wall- aneurysm
erosion (of fibrous cap)- thrombus

Question 16

define thrombus

Answer 16

Solidification of blood contents formed in the vessel during life.

Question 17

what are the characteristics of a clot which make it different to a thrombus

Answer 17

stagnant
enzymatic process
elastic
adopt to the shape of the vessels

Question 18

what are the characteristics of a thrombus which make it different to a clot.

Answer 18

during life
dependent on platelets
firm.

Question 19

what cell is needed in thrombus formation

Answer 19

platelets.

Question 20

what bone marrow cell gives rise to platelets

Answer 20

megakaryocytes.

Question 21

what is the function of platelets, to what molecule do they bind in endothelial injury

Answer 21

circulate in the blood stream

Bind to collagen exposed by endothelial damage and become activated

Question 22

what molecules do platelets secrete.

Answer 22

Alpha granules: fibrinogen, fibronectin, PDGF

Dense granules: chemotactic chemicals

Question 23

how is virchow’s triad important in atherosclerosis formation

Answer 23

platelet adhesion and subsequent thrombus formation requires change in intimal surface of the vessel, blood flow and blood constituents.

Question 24

what is the pathogenesis of arterial thrombosis

Answer 24

plaque ruptures- turbulent flow and intimal change.
Hyperlipidaemia- change in blood constituents.
Platelets bind and fibrin is produced entrapping RBC.
Thrombus propagation-infront of thrombus is laminar flow and behind thrombus is turbulent flow.

Question 25

what is the pathogenesis of venous thrombosis.

Answer 25

``` intimal change- valves change in bloodflow immobile change in blood constituents- prothrombogenic Factor V leiden oestrogen inflammatory mediators ```

Question 26

what are thrombi of the heart also known as

Answer 26

mural thrombi.

Question 27

How does MI predispose the heart to thrombi

Answer 27

surface of the heart becomes sticky so the platelets adhere

Question 28

How does arrhythmia's predispose the heart to thrombi

Answer 28

stasis occurs and hence a thrombus can form.

Question 29

what does a thrombus predispose you to

Answer 29

``` occlusion of a vessel resolution incorporation into the vessel recanalisation embolisation ```

Question 30

define embolisation

Answer 30

A mass of material in the vascular system able to lodge in a vessel and block it

Question 31

what are the acquired risk factors of pulmonary emboli

Answer 31

immobility, malignancy, previous VTE, heart failure, oestrogen's, obesity, pregnancy, renal disease, smokers

Question 32

what are the genetic and hereditary factors of pulmonary emboli

Answer 32

Thrombotic disorders FV Leiden Protein S defieiciency

Question 33

what are the symptoms of DVT

Answer 33

looks hot, red swollen

Question 34

what are the clinical symptoms of of small PE

Answer 34

asymptomatic, if multiple may result in pulmonary hypertension

Question 35

what are the clinical symptoms of of medium PE

Answer 35

acute respiratory and cardiac failure (V/Q mismatch, RV strain)

Question 36

what are the clinical symptoms of of large PE

Answer 36

“saddle emboli”

Question 37

define paradoxical emboli

Answer 37

Hole in the heart means that clot can travel from the left to the right side of the heart and then lodge into a pulmonary vessel.

Question 38

where do systemic emboli arise

Answer 38

in the heart or within the arterial circulation.

Question 39

where do atheromas arise from

Answer 39

eroded plaques

Question 40

where do platelet emboli arise from

Answer 40

atherosclerotic plaques.

Question 41

where do infective emboli arise from

Answer 41

Usually from the vegetation’s on infected heart valves

Question 42

what are the main causes of infective emboli

Answer 42

prosthetic valve and IV drug use.

Question 43

consequence of infective emboli

Answer 43

mycotic aneurysm formation.

Question 44

define tumour embolism

Answer 44

tumour section dislodges into blood vessel.

Question 45

what are the 2 types of gas embolism

Answer 45

• Air (vessel opened into the air) - Obstetric procedures / chest wall injury • Nitrogen – Decompression sickness (“the bends”) – Divers, tunnel workers – Nitrogen bubbles enter bones, joints and lungs

Question 46

In an oxygen gas emboli what must the amount of oxygen be to cause significant effects

Answer 46

100 ml.

Question 47

what causes amniotic fluid embolism- pathophysiology.

Answer 47

Increased uterine pressure during labour may force AF into maternal uterine veins

Question 48

what causes fat embolism

Answer 48

significant trauma post menopause

Question 49

what is a consequence of amniotic emboli

Answer 49

Lodge in lungs leading to respiratory distress

Question 50

what is a consequence of fat embolism

Answer 50

Sudden onset of respiratory distress

Question 51

what causes foreign body embolism

Answer 51

Particles injected intravenously

Question 52

where do atheromas commonly form

Answer 52

lower limbs after and angiogram which can cause the plaque to dislodge.

Question 53

define atheroma

Answer 53

Atheroma is a fatty deposit in the intima, which is the inner lining,

Question 54

does atheroma predispose to atherosclerosis

Answer 54

Yes