Hemostasis, Platelet, Coagulation, Anti-coagulant Drugs (Exam 3)

Question 1

What is hemostasis?

Answer 1

arrest of bleeding by the vasoconstriction and coagulation

Question 2

What are the 3 functions of platelets?

Answer 2

platelet adhesion | release reaction | platelet aggregation

Question 3

Describe platelet adhesion function of the platelet?

Answer 3

after vessel injury = platelets adhere to sub-endothelial connective tissues

Question 4

What is platelet adhesion dependent on?

Answer 4

the presence of factor 8 (VIII) = von-Willebrand factor

Question 5

What are the 3 molecules found in the granules of platelets?

Answer 5

ADP, thromboxane A2, serotonin

Question 6

Describe the release reaction function of platelets?

Answer 6

platelet exposed to collagen = release granule contents

Question 7

Describe the platelet aggregation function of the platelet?

Answer 7

ADP and ThromboxaneA2 release = additional platelets aggregate to injury site = platelets swell = platelets adhere together = aggregation = factor 3 exposed for coagulation protein complex formation

Question 8

What is the role of ADP?

Answer 8

attracts more platelets to the site

Question 9

What is the role of serotonin?

Answer 9

promotes vasoconstriction

Question 10

What is the role of Thromboxane A2?

Answer 10

promotes platelet aggregation, degranulation, and vasoconstriction

Question 11

Why is vasoconstriction important in blood coagulation?

Answer 11

slow blood flow to injury site to plug the hole

Question 12

What is the protein factor that initiates the coagulation process at the injury site?

Answer 12

factor III (factor 3) = platelet thromboplastic factor 3

Question 13

What is the protein factor that acts as the connecting piece for all of the processes carried out in coagulation?

Answer 13

factor XIII (factor 13)

Question 14

What is blood coagulation?

Answer 14

the process of forming a clot

Question 15

What is the result of blood coagulation?

Answer 15

platelets aggregate at site of clot | fibrin ties up platelets to form clot

Question 16

What are the 3 pathways involved in blood coagulation?

Answer 16

intrinsic activation, extrinsic activation, common pathway

Question 17

What is the end product of the Intrinsic Activation Pathway?

Answer 17

Factor IXa (factor 9a)

Question 18

What is the end product of the Extrinsic Activation Pathway?

Answer 18

Factor VIIa (factor 7a)

Question 19

What are the protein factors and mineral needed to create protein factor Xa (factor 10a)?

Answer 19

7a + 9a + Ca2+ = 10a

Question 20

What is the end product of the common pathway?

Answer 20

thrombin

Question 21

What is the role of factor XIIIa (factor 13a)?

Answer 21

converts fibrin into stable form by making covalent bonds

Question 22

How is fibrin made? What are the factors needed?

Answer 22

thrombin drives fibrinogen (with Ca2+) = fibrin

Question 23

What will happen if one of the protein factors are missing from the blood coagulation process?

Answer 23

cause a disease (specific to which factor is missing)

Question 24

What is the treatment for missing coagulation protein factors?

Answer 24

blood transfusions

Question 25

What are the 4 ways coagulation is controlled?

Answer 25

factor concentration-dependent | liver | anti-thrombin | plasmin

Question 26

What is significant about factor concentration dependence in order to control coagulation?

Answer 26

concentration of protein factors need to be high enough to initiate the hemostasis process

Question 27

How does the liver control coagulation?

Answer 27

destroy unused factors in parenchymal cells

Question 28

What is the role of anti-thrombin? What activates it?

Answer 28

inactivates thrombin | heparin activates anti-thrombin

Question 29

What does plasmin do?

Answer 29

digests fibrin, fibrinogen, factors V and VIII (factors 5 and 8)

Question 30

What is the number one observation on people who suffer from coagulation factor deficiency?

Answer 30

hematoma on thigh due to prolonged-sitting

Question 31

What are the 3 lab screening tests used in diagnosing coagulation disorders?

Answer 31

prothrombin time (PT) | activated partial thromboplastic time (APTT) | thrombin time (TT)

Question 32

What is the function of the prothrombin time (PT) screen test?

Answer 32

tests extrinsic and common pathways

Question 33

What is the function of the activated partial thromboplastic time (APTT) screen test?

Answer 33

tests intrinsic and common pathways

Question 34

What is the function of thrombin time (TT) screen test?

Answer 34

tests fibrinogen to fibrin conversion

Question 35

What is Hereditary Hemorrhagic Telangiectasis (HHT)?

Answer 35

vascular and platelet genetic autosomal dominant trait disorder

Question 36

What are the symptoms of Hereditary Hemorrhagic Telangiectasis (HHT)?

Answer 36

abnormal blood vessel formation | skin lesions | a lot of nose bleeds

Question 37

What reduces coagulation in Hereditary Hemorrhagic Telangiectasis (HHT)?

Answer 37

asprin

Question 38

What are the 3 causes of thrombocytopenia?

Answer 38

failure platelet production | increased destruction of platelets | abnormal distribution of platelets at unnecessary sites

Question 39

What is Hemophilia A?

Answer 39

most common coagulation disorder | genetic, found on X-chromosome (sex-linked)

Question 40

What is Hemophilia A due to?

Answer 40

absence or low level of factor VIII:C (factor 8) procoagulant activity clotting activity

Question 41

Who are most affected by Hemophilia A? Who are the carriers of Hemophilia A?

Answer 41

men | women = carriers

Question 42

What is the characteristic of Hemophilia A?

Answer 42

factor VIII:C (factor 8) procoagulant activity deficiency

Question 43

Where are the main sites of hemorrhage for Hemophilia A?

Answer 43

muscle, joints, post-trauma or surgery

Question 44

What is the most serious complication for Hemophilia A?

Answer 44

antibodies against factor VIII (factor 8)

Question 45

What is the treatment of Hemophilia A?

Answer 45

factor VIII (C-antigen) and desmopressin = increase plasma factor VIII (factor 8) production

Question 46

What is Hemophilia B?

Answer 46

Similar clinical features as Hemophilia A just with factor IX (factor 9)

Question 47

What is another name for Hemophilia B?

Answer 47

Christmas Disease

Question 48

What is the characteristic of Hemophilia B?

Answer 48

factor IX (factor 9) deficiency

Question 49

What is the treatment of Hemophilia B?

Answer 49

factor IX (factor 9) concentrates

Question 50

What is von-Willebrands disease?

Answer 50

SAME as Hemophilia A BUT different = deficient levels if factor VIIIR:AG (factor 8) related antigen

Question 51

What is disseminated intravascular coagulation (DIC)?

Answer 51

coagulation happens everywhere in body = exhaust all of available coagulation factors

Question 52

What are the 2 causes of disseminated intravascular coagulation (DIC)?

Answer 52

entry of pro-coagulant material from: transfusion, snakebites, premature separation of placenta | widespread endothelial damage and collagen exposure (septecemia, viral infection)

Question 53

What is the treatment for disseminated intravascular coagulation (DIC)?

Answer 53

fresh frozen plasma | supportive fibrinogen and platelet

Question 54

What are the 2 anti-coagulant drugs discussed? Which one is the most commonly used one?

Answer 54

heparin (most common) | coumarin (warfarin)

Question 55

How is heparin administered and what is its half-life?

Answer 55

intravenously | ~1 hour

Question 56

Where was coumarin first found?

Answer 56

in cattle

Question 57

What is the function of coumarin?

Answer 57

(anti-vitamin K) decreases activity of anti-vitamin-K dependent factors 2, 7, 9, 10 (factors II, VII, IX, X)

Question 58

How is coumarin administered?

Answer 58

orally