Blood Coagulation and Wound Healing

Question 1

what is the process of blood clotting/ coagulation? (6)

Answer 1

injury/rupture to blood vessel
blood vessel around wound constricts (reduces blood flow to the damaged area)
activated platelets stick to the injury site
platelets become sticky and clump together to form a platelet plug
platelets and damaged tissue release clotting factors
blood clotting mechanism to form fibrin which acts like a mesh to stop the bleeding

Question 2

primary hemostasis

Answer 2

vasoconstriction and platelet response

Question 3

what mediates platelet aggregation at the site of injury in primary hemostasis (4)

Answer 3

platelet receptors
platelet-derived agonists
platelet-derived adhesive proteins
plasma-derived adhesive proteins

Question 4

secondary hemostasis

Answer 4

clotting cascade

Question 5

what does secondary hemostasis consist of?

Answer 5

the cascade of coagulation serine proteases that culminates in cleavage of soluble fibrinogen by thrombin

Question 6

Thrombin cleavage generates insoluble fibrin that forms a cross-linked fibrin mesh at

Answer 6

the site of an injury

Question 7

fibrin generation occurs simultaneously to

Answer 7

platelet aggregation

Question 8

what do clotting factors do

Answer 8

convert prothrombin to thrombin

Question 9

what does thrombin do

Answer 9

convert fibrinogen to fibrin (insoluble)

Question 10

damaged blood vessel

Answer 10

injury to vessel lining triggers the release if clotting factors

Question 11

formation of platelet plug

Answer 11

vasoconstriction limits blood flow and platelets form a stick plug

Question 12

development of clot

Answer 12

fibrin strands adhere to the plug to form an insoluble clot

Question 13

platelets release important signaling molecules upon initial binding to

Answer 13

collagen

Question 14

Platelets that stick to collagen undergo a release reaction, in which they secrete (3)

Answer 14

ADP, serotonin, and thromboxane A2

Question 15

Serotonin and thromboxane A2 cause

Answer 15

vasoconstriction

Question 16

platelet plug process

Answer 16

ADP and thromboxane A2 attract other platelets and make them stick to the growing mass of platelets that are stuck to the collagen in the broken vessel

Question 17

what can platelets secrete?

Answer 17

serotonin

Question 18

what does serotonin cause?

Answer 18

blood vessels to spasm, decreasing blood flow to that area

Question 19

the initial binding of platelets to vWF is mediated by

Answer 19

glycoproteins that are necessary for platelet tethering (ex. loosely bound), but do not promote strong adhesion (ex. GPlb amd la are not enough, even in conditions of high shear)

Question 20

firm adhesion of platelets to the sub endothelial is mediated by a glycoprotein called

Answer 20

GP2B/3A

Question 21

the GP2B/3A integrins on resting platelets bind

Answer 21

poorly to its ligands

Question 22

GP2B/3A intern ligands (2)

Answer 22

vWF or fibrinogen

Question 23

upon platelet activation (by GPV1), GPV2B/3A undergoes a conformational change that reveals a previously hidden binding site for

Answer 23

vWF or fibrinogen

Question 24

activated GP2B/3A binds to vWF at the subendothelial surface to promote

Answer 24

strong adhesion to the vessel wall

Question 25

primary aggregation

Answer 25

strong adhesion to the vessel wall

Question 26

what does GP2B/3A binding to fibrinogen play a role in?

Answer 26

platelet-platelet interactions

Question 27

AGGREGOMETER TRACINGS record the aggregation of platelets in platelet-rich plasma in response to

Answer 27

an aggregating agent

Question 28

in these cases, the aggregating agents are (2)

Answer 28

collagen and two concentrations of ADP

Question 29

The initial increase in light transmission is due to

Answer 29

dilution by the agent, the small downward deflection to a change in platelet shape and the subsequent increase to aggregation

Question 30

With collagen there is a lag before ADP is secreted by the platelets to cause aggregation; when ADP is supplied directly the effect is

Answer 30

faster

Question 31

The effect of a low concentration of ADP is reversed as enzymes

Answer 31

destroy ADP

Question 32

The extrinsic pathway is activated by

Answer 32

external trauma that causes blood to escape from the vascular system

Question 33

is the intrinsic or extrinsic pathway faster?

Answer 33

extrinsic

Question 34

what factor does the extrinsic pathway involve?

Answer 34

7

Question 35

The intrinsic pathway is activated by (5)

Answer 35

trauma inside the vascular system, and is activated by platelets, exposed endothelium, chemicals, or collagen

Question 36

what factors does the intrinsic pathway use? (4)

Answer 36

12 10 9 8

Question 37

common pathway

Answer 37

when the intrinsic and extrinsic pathways meet and finish the pathway of clot production

Question 38

what factors are involves in the common pathway? (4)

Answer 38

1 2 5 10

Question 39

The coagulation factors are generally

Answer 39

serine proteases

Question 40

serine proteases act by

Answer 40

cleaving downstream proteins

Question 41

The exceptions are (4)

Answer 41

tissue factor, FV, FVIII, FXIII

Question 42

Tissue factor, FV and FVIII are ---, and Factor XIII is a ---

Answer 42

glycoproteins | transglutaminase

Question 43

The coagulation factors circulate as

Answer 43

inactive zymogens

Question 44

The coagulation cascade is therefore classically divided into .

Answer 44

three pathways extrinsic, intrinsic, common

Question 45

fat soluble vitamins (4)

Answer 45

D E A K

Question 46

the platelet plug that initially forms is not ..

Answer 46

strong enough by itself to fully prevent further bleeding

Question 47

a fibrin mesh is laid down to

Answer 47

further reinforce and strengthen the platelet plug

Question 48

what is cross linking of fibrin catalyzed by?

Answer 48

transglutaminase or factor 13

Question 49

In circulation, plasminogen adopts a ---, activation-resistant conformation

Answer 49

closed

Question 50

Upon binding to clots, or to the cell surface, plasminogen adopts an open form that can be converted into

Answer 50

active plasmin

Question 51

plasminogen can be converted to active plasmin by a variety of enzymes, including (4)

Answer 51

tissue plasminogen activator (tPA), urokinase plasminogen activator (uPA), kallikrein, and factor XII (Hageman factor)

Question 52

Fibrin is a cofactor for plasminogen activation by

Answer 52

tissue plasminogen activator

Question 53

Urokinase plasminogen activator receptor (uPAR) is a cofactor for plasminogen activation by

Answer 53

urokinase plasminogen activator