Normal haemostasis

Question 1

There must be a balance between platelet deposition and clotting mechanism. T/F

Answer 1

True

Question 2

Haemostasis means

Answer 2

Stoppage of blood

Question 3

The five haemostasis responses

Answer 3

Vasoconstriction
Platelet plug formation
Fibrin Clot formation
Coagulation inhibition 
Clot degradation

Question 4

The reflex of vasoconstriction is caused by

Answer 4

Initial reduction of blood flow to injury area

Question 5

Activation of platelets and coagulation factors is caused by

Answer 5

Reduced blood flow

Question 6

Adhesion molecules of endothelial cells

Answer 6

P and e selectins
VCAM- Vascular cell adhesion molecule
Von willebrands

Question 7

What initiates coagulation

Answer 7

Tissue factor

Question 8

A vasodilator and inhibition of platelet aggregation

Answer 8

Prostacyclin and NO

Question 9

What is a platelet-collagen adhesion

Answer 9

Von willebrand

Question 10

What inhibits blood coagulation

Answer 10

Activated protein C
Anti-thrombin
Protein S

Question 11

What fibrinolyse

Answer 11

Tissue plasminogen

Question 12

Diameter of platelets

Answer 12

3.0 by 0.5 um in diameter

Question 13

Adhesion of platelets to collagen is by

Answer 13

GPIa

Question 14

Adhesion of platelets to von willebrand is by and also fibrinogen receptors are

Answer 14

GPIIa, GPIIb/IIIa

Question 15

Platelet-platelet aggregation is mediated by

Answer 15

Fibrinogen receptors on platelets

Question 16

Platelets have 3 intracellular granules

Answer 16

Lyzozymes
Alpha( VWF, PDGF,)
Dense(ADP,ATP, serotonin and calcium)

Question 17

What provides procoagulant surface

Answer 17

Platelets

Question 18

3 major mechanism of platelet functions

Answer 18

Adhesion
Aggregation
Release reactions and amplification

Question 19

Cross-linking of platelets during aggregation is by

Answer 19

GPIIb/IIIa receptors with fibrin bridge

Question 20

What potentiates platelets aggregation

Answer 20

VWF, Collagen, Thrombin

Question 21

Functions of TXA2 is used for

Answer 21

Secondary amplification. Increase platelet

Question 22

Serine protease are vitamin K dependent. True/false

Answer 22

True

Question 23

Serine proteases

Answer 23

Factor
2,7,9,10,11,12 and
Prekallikrein

Question 24

Site of clotting factors

Answer 24

Major- Liver hepatocytes except FVIII produced in the sinusoids
Minor- platelets, Endothelial , spleen

Question 25

Extrinsic pathway requires

Answer 25

TF

Question 26

Common route to fibrin formation is on

Answer 26

Factor X

Question 27

Activation of intrinsic pathway is by

Answer 27

subendothelial collagen

Question 28

Characteristics of intrinsic pathway

Answer 28

Slow to generate and activate factors

Greater number of procoagulants

Question 29

What is the contact activation pathway

Answer 29

Plasma and negatively charged foreign surface.

Question 30

Activation of Factor VII leads through

Answer 30

Extrinsic pathway

Question 31

Thrombin generation is dependent on 3 enzyme systems

Answer 31

Extrinsic xase -(VIIa, PL, ca2+
Intrinsic xase- ( VIIIa, IX, PL, Ca2+)
Prothrombinase complex-( II, Xa, Va, PL, Ca2+)

Question 32

What plays d Central role in hemostasis

Answer 32

Thrombin

Question 33

2 groups of naturally occuring blood coagulation inhibitors

Answer 33

• serine protease inhibitors( Antithrombin, Heparin cofactor II)
• activated cofactors inhibitors- protein C, protein S, Thrombin

Question 34

Thrombin binds to the endothelial receptor thrombomodulin resulting in

Answer 34

activation of protein C

Question 35

Activated protein C inhibits

Answer 35

V and VIII

Question 36

Fibrinolytic system includes

Answer 36

Pro enzyme- Plasminogen
Plasminogen activators
Fibrinlytic inhibitors