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Flashcards in Hemostasis Deck (34)
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1

What is the life span of a platelet?

5-10d

2

How quickly does a platelet plug form?

Within 5min

3

What are platelets attracted to in vascular endothelium when it is disrupted?

Collagen

4

What are the three reactions that platelets undergo when they come in contact with collagen?

Adhesion and shape change, aggregation, secretion

5

Exposure of subendothelium and platelet adhesion depends on what factor?

von Willebrand factor

6

When platelets are activated, what do they do?

Attach to each other and release chemotactic factors

7

What is the coagulation cascade?

Series of reactions leading to fibrin clot formation

8

Cross-linking fibrin, trapping RBCs, plasma, and PLTs w/in platelet plug

Coagulation cascade (fibrin clot)

9

What becomes absorbed to fibrin fibers as they develop?

Thrombin

10

What does anti-thrombin in the blood stream do?

Inactivates thrombin and prevents excessive clotting

11

What can bind to anti-thrombin and make it more potent to prevent coagulation?

Heparin

12

How will mucous membranes of a hemodynamically compromised patient appear?

Petechiation, echymosis, bleeding

13

What are the key tests in assessment of primary hemostasis?

PLT count and bleeding time

14

At what PLT level do dogs and cats have spontaneous bleeding?

<30k/uL

15

What is normal buccal mucosal bleeding time?

<4min

16

What are the two most common tests used to evaluate the intrinsic pathway?

Activated clotting time (ACT) and activated partial thromboplastin time (aPTT)

17

What is normal ACT?

60-90sec

18

Measures time required for fibrin clot formation in fresh whole blood

Activated clotting time

19

What pathways does ACT and aPTT test?

Intrinsic and common pathways

20

What test can you to to evaluate the extrinsic pathway?

Prothrombin time (PT)

21

Which pathway is Factor 7 part of?

Extrinsic pathway

22

Why is factor 7 most reliable for measuring hemostasis?

Shortest half-life

23

What are Vit K dependent coag factors?

2, 7, 9, 10

24

What is platelet dysfunction most commonly due to?

Low concentration of vW factor

25

Which dog breed is most predisposed to platelet dysfunction d/t low vWf?

Doberman pinscher

26

What is the inheritability of vWf deficiency?

Autosomal dominant

27

How do you treat PLT dysfunction d/t vWf deficiency?

DDAVP

28

What are x-linked factor deficiencies?

Hemophilia A and B

29

What factor is deficient with Hemophilia A?

Factor 8

30

What factor is deficient with Hemophilia B?

Factor 9