Overview of Hemostasis

Question 1

what is hemostasis

Answer 1

the ability of the body’s systems to maintain the integrity of the blood and blood vessels
CLOTTING

Question 2

4 main steps to achieve hemostasis

Answer 2

1. primary hemostasis - form platelet plug
2. secondary hemostasis - form mesh of fibrin
3. fibrinolysis - removal of plug
4. restoration of vessel patency - tissue repair

Question 3

players in primary hemostasis

Answer 3

platelets and von Willebrand factor

Question 4

players in secondary hemostasis

Answer 4

clotting factors

Question 5

where are most coagulation factors produced

Answer 5

the liver

Question 6

where is Factor III produced

Answer 6

endothelial cells

Question 7

where are Von Willebrands produced

Answer 7

endothelial cells

Question 8

which factors require Vitamin K for activation

Answer 8

II, VII, IX, X
proteins C and S

Question 9

which Vitamin K factors have the shortest half life

Answer 9

Factor VII - 5 hours

Question 10

factors in intrinsic pathway

Answer 10

XII, XI, IX, VIII

Question 11

factors in extrinsic pathway

Answer 11

III, VII

Question 12

factors in common pathway

Answer 12

X, II, I, XIII

Question 13

thrombocytopenia

Answer 13

decrease in platelet count

Question 14

thrombocytosis

Answer 14

increase in platelet count

Question 15

thrombocytopathia

Answer 15

dysfunctional platelets

Question 16

3 general ways to have thrombocytopenia

Answer 16

decrease in production
increase in consumption
sequestration

Question 17

2 main causes for thrombocytosis

Answer 17

reactionary: chronic inflammation, iron deficiency, Cushings
primary: megakaryocyte leukemia

Question 18

MPV definition

Answer 18

Mean Platelet Volume

Question 19

BMBT definition

Answer 19

Buccal Mucosal Bleed Time

Question 20

what does BMBT test for

Answer 20

platelet vessel interaction (primary hemostasis)

Question 21

why is cuticle bleed not a great test to assess platelet function

Answer 21

difficult to standardize
painful
does not differentiate primary and secondary hemostasis

Question 22

which tests can be used to assess the intrinsic pathway

Answer 22

Activated Clotting Time (ACT)
Partial Thromboplastin Time (PTT/aPTT)

Question 23

which tests can be used to asses the common pathway

Answer 23

Activated Clotting Time (ACT)
Primary Thromboplastin Time (PTT/aPTT)
Prothrombin Time (PT)

Question 24

which tests can be used to asses the extrinsic pathway

Answer 24

Prothrombin Time (PT)

Question 25

why would a dog with decreased platelets but an increased MPV not have an issue with primary hemostasis

Answer 25

larger platelets are more hemostatically active