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Systemic Pathology Test 2 > Coagulation > Flashcards

Flashcards in Coagulation Deck (70):
1

What are the 3 constituents of the hemostatic system?

Coagulation proteins, endothelium, platelets

2

What is the purpose of the coagulation system

Thrombin formation leading to a fibrin clot

3

What is the purpose of the fibrinolytic system?

To lyse the clot

4

What is the purpose of the anticoagulant system?

Regulate all the enzymes so neither the coagulation or fibrinolytic system occurs in excess

5

What is the first stage of coagulation?

Vasoconstriction

6

In the first stage of coagulation, what causes vasoconstriction?

Reflexes and endothelin release from the site of injury

7

What is the second stage of coagulation?

Primary hemostasis where platelets aggregate

8

In the second stage of coagulation, how do platelets attach to collagen?

Via von willebrand factor

9

What substances are released from platelet granules and what does this cause?

ADP and TXA2 leading to further recruitment of platelets and the formation of a hemostatic plug

10

What is the 3rd stage of coagulation?

Secondary hemostasis or fibrin formation

11

What is released in the third stage of coagulation and what affect does it have?

Tissue factor, leads to thrombin activation. A plug is formed and WBC and RBCs are trapped

12

The 4th stage of coagulation is?

Crosslinking of fibrin and fibrinolysis

13

What two substances are released in the tertiary stage and what do they do?

t-PA for fibrinolysis
Thrombomodulin which blocks the coagulation cascade

14

Which factors are vitamin K dependent?

2,7,9,10, S, C

15

What testing good specimens what is used as an anticoagulant?

Sodium citrate

16

Prothrombin time measures what pathway?

Extrinsic to common

17

What 3 things can cause PT increase?

1. VII deficiency or deficiency in other factors or inhibitors to them
2. Vitamin K deficiency from liver disease, warfarin, or antibiotics
3. Liver disease
4. Deficiencies in common factor 1,2,5,10

18

aPTT measures what pathway?

Intrinsic to common

19

What is the heparin effect?

Increased aPTT time due to use of this injectable anticoagulant

20

What can cause factor deficiency or inhibitor?

Hemophilias A, B, and C and amyloid disorder

21

The thrombin time test is for?

Fibrin generation test, fibrinogen or factor 1

22

D-dimer is an indication of?

Fibrin has been formed and degraded

23

D-dimer and FDP are elevated in what conditions, what type of cancer?

1. DIC
2. Thrombosis
3. End stage liver disease
4. Mucin-secreting adenocarcinomas

24

In a mixing study, if clotting times are prolonged this means?

An inhibitor is present

25

In a mixing study, if clotting times decrease this means?

There is a factor deficiency

26

When do factors in neonates reach adult levels? Which factor is typically present at a similar level?

6 months

Factor VIII

27

How is hemorrhagic telangiectasia inherited? What does it cause?

Autosomal dominant, leads to abnormal blood vessel formation in the skin and organs. Leads to nosebleed and bleeding of the GI tract and other organs

28

How do you treat hemorrhagic telangiectasia?

Avoid bleeding as much as possible and supplement iron

29

What is Elhers-Danlos syndrome?

A group of inherited CT disorders caused by defects in collagen I and III synthesis

30

Patients with Elhers-Danlos have what symptoms?

Thin skin that is pale and you can see their veins, bruise very easily

31

What are the four acquired coagulation protein defects?

1. Factor X deficiency
2. Vitamin K deficiency
3. DIC
4. Liver disease

32

What factor is deficient in the 3 hemophilias?

A is factor 8
B is 9
C is 11

33

What is the severity of most hemophiliacs?

Severe

34

What can cause bleeding in those with mild hemophilia?

Surgery or major trauma

35

Female carriers of hemophilia often have factor VIII activity in what range?

Greater than 50% so normal

36

Lab tests on carriers will show?

Normal PTT but increased vWF to factor VIII ratio, 2:1 as opposed to 1:1

37

What can cause the presence of factor VIII inhibitors in non-hemophiliacs?

Idiopathic conditions, SLE or rheumatoid arthritis, lymphomas and solid tumors, drug reactions, pregnancy and postpartum state

38

How is hemophilia C inherited?

Autosomal recessive

39

Hemophilia C causes bleeding of what severity?

Mild

40

Disseminated intravascular coagulation is caused by?

Numerous microvascular clots due to a substance that behaves similar to tissue factor.

41

Disseminated intravascular coagulation leads to?

Bleeding diathesis

42

What are causes of disseminated intravascular coagulation?

Snake venom, infections, obstetric complications, mucin-secreting adenocarcinomas

43

What 4 things are decreased in DIC?

Platelet count, factor assay, fibrinogen, and antithrombin

44

Thrombophilia is characterized by?

Hypercoagulability and an increased propensity for thrombosis

45

What is the most common cause of acquired thrombophilia?

Antiphospholipid syndrome

46

What are the two common clinical features of inherited thrombophilia?

Deep vein thrombosis of lower limbs, pulmonary embolism

47

What two rare clinical features are characteristic of inherited thrombophilia?

Mesenteric vein thrombosis and cerebral vein thrombosis

48

Protein C deficiency is inherited by?

Autosomal dominant

49

The initial thromboembolic episode occurs normally or spontaneously?

Usually spontaneously

50

Protein C deficiency usually affects what veins?

Deep veins of the leg, ileofemoral veins, and mesenteric veins

51

Describe the 2 types of protein C deficiency?

Type 1 there is decreased protein C
Type 2 there is decreased functionality of protein C

52

How does homozygous protein C deficiency present itself in newborns?

Purpura fulminans

53

What is protein S?

An essential cofactor of protein C

54

How does protein S circulate?

Freely or complex to c4b binding protein

55

What is the most common hereditary thrombophilia?

APC resistance or activated protein C

56

How is APC resistance inherited?

Autosomal dominant

57

APC resistance is associated with a mutation in what gene>

Factor V gene, substitute arginine for glutamine

58

What is the reference range for INR?

0.9-1.3

59

What level INR indicates a high chance of bleeding? High chance of clot? What is the target range for anticoagulant use?

5, 0.5, 2-3

60

Increased thrombin time if associated with what congenital disorders?

Afibrinogemia and hypofibrinogemia

61

Results of factor activity tests for normal adults fall between?

60-150%

62

In those with factor VIII inhibitor a mixing study will show?

Immediate correction of pTT that prolongs after 1 hour

63

Hemophilia C is a deficiency in? What is the result?

Factor XI, results in mild bleeding

64

What causes inherited afibrinogenemia and hypo?

Autosomal recessive mutations that truncate the protein

65

What is associated with afribogenemia?

Prolonged pt and ptt and bleeding disorder similar to moderate to severe hemophilia A

66

What is the first manifestation of inherited hypo or afibrinogenemia?

Umbilical cord hemorrhage then life long bleeding diasthesis

67

Factor 13 deficiency will result in? Blood test will show?

Mild delayed bleeding, normal Pt, ptt, and tt

68

Amyloidosis will result in decreased?

Factor X

69

Vitamin K deficiency results in decreased?

Factors 2,7,9,10

70

Pregnancy results in decreased and increased?

Decreased protein S, increased vWF