Coagulation and Thrombosis Oct16 M3

Question 1

normal hemostasis def

Answer 1

blood clot formation to limit bleeding

Question 2

thrombosis def

Answer 2

patho counterpart to hemostasis (blood clots in intact vessels)

Question 3

3 elements controlling hemostasis and thrombosis

Answer 3

endothelial cells and vascular wall
platelets
coagulation cascade

Question 4

4 steps of hemostasis

Answer 4

• arteriolar vasconstriction
• primary hemostasis (initial platelet plug)
• secondary hemostasis (stabilization of platelet plug)
• fibrinolysis and dissolution

Question 5

vascular injury: endothelial cells release what

Answer 5

• endothelin: vasoconstriction

- procoagulative factors

Question 6

way vessels constrict other than endothelin

Answer 6

neurogenic mechanism (SM reflex)

Question 7

primary hemostasis: main component and 2 roles

Answer 7

platelets

• seal defects
• recruit and activate coagulation factors

Question 8

3 steps of primary hemostasis

Answer 8

platetet adhesion, platelet activation, platetet aggregation

Question 9

how platelet adhesion occurs

Answer 9

platelet bind to collagen by binding to vWF with receptor glycoprotein 1b

Question 10

how vWF got on collagen and what collagen

Answer 10

collagen of ECM made available after endothelial cell injury. vWF bound to it

Question 11

platelet activation def

Answer 11

platelets undergo irreversible shape change and secrete granules with calcium and Thromboxane A2

Question 12

what calcium and thromboxane A2 secreted by platelets do

Answer 12

calcium is a cofactor for several coagulation factors

TxA2 activates other platelets

Question 13

platelet aggregation def

Answer 13

binding to fibrinogen of nearby platelets with a R

Question 14

normally synthesized anti-coagulation factors (by normal endothelium)

Answer 14

Prostaglandin PGI2 and NO

Question 15

aspirin mode of action

Answer 15

inhibits COX 2, enzyme required to produce TxA2 and PG

Question 16

secondary hemostasis def

Answer 16

coagulation cascade leading to stabilization of platelet plug

Question 17

end result of coagulation cascade

Answer 17

activation of prothrombin into thrombin which cleaves fibrinogen into fibrin

Question 18

fibrin roles (2)

Answer 18

• polymer to reinforce platelet plug

- activate more platelets

Question 19

coagulation cascade def

Answer 19

successive series of enzymatic reactions where pro enzymes cleaved into enzymes

Question 20

lab tests used to screen for coagulation disorders

Answer 20

PT, PTT, INR (normalization of PT)

Question 21

some factors required for coagulation cascade

Answer 21

phospholipids, calcium, vitamin K

Question 22

fibrinolysis def

Answer 22

breaking down fibrin platelet plug

Question 23

fibrinolysis trigger

Answer 23

plasminogen activators activate plasminogen into plasmin, plasmin breaks down fibrin

Question 24

Virchow’s triad on what controls thrombosis

Answer 24

Endothelial injury, abnormal blood flow, hypercoagulability

Question 25

how abnormal blood flow can lead to thrombosis

Answer 25

turbulence in high flow regions: zones of low flow

Question 26

thromboembolus def

Answer 26

thrombus fragile and breaks from vascular structure to propagate

Question 27

embolus

Answer 27

any substance carried by blood

Question 28

2 main types of thrombi

Answer 28

arterial and venous

Question 29

arterial thrombi charact

Answer 29

zones of arterial turbulence, atherosclerotic plaque

Question 30

venous thrombi charact

Answer 30

zones of stasis

Question 31

thrombus on microscope

Answer 31

lines of Zahn (rainbow)

Question 32

venous thrombi consequence

Answer 32

congestion, edema, embolisation (especially if above knee joint)

Question 33

arterial thrombi consequence

Answer 33

tissue infarction by obstruction

Question 34

Disseminated intravascular coagulation def

Answer 34

widespread thrombosis in microcirculation

Question 35

Factors that influence infarct development

Answer 35

rate of occlusion, collaterol blood supplies, tissue susceptibility to ischemia, blood oxygenation

Question 36

how infarcts classified

Answer 36

(colour)

red, white

Question 37

red infarct charact

Answer 37

hemorrhagic: venous occlusion, when flow established after infarction, 2 circulations

Question 38

white infarct charact

Answer 38

anemic infarct. (arterial occlusions in organs with end arterial circulation: heart, spleen, kidney)

Question 39

lung what type of infarct and why

Answer 39

red bc 2 circulations

Question 40

PE: cause in most cases

Answer 40

thrombi in large deep veins of the leg

Question 41

how PE can be deadly

Answer 41

if blocks large pulmonary arteries

Question 42

consequences of PE on pulm circulation

Answer 42

pulmonary hypertension, RHF, cor pulmonale, ischemia to downstream parenchyma