H78: Bleeding and Thrombosis

Question 1

Briefly describe the clotting cascade

Answer 1

TF is exposed and bound by VIIa then IX and X are activated.
IXa can activate X through the IXa/VIIIa/X complex to become the Xa/Va/prothrombin complex in order to produce fibrin out of fibrinogen.

Question 2

Four main physiologic antithrombotic pathways and their action point:

Answer 2

TFPI bloxks the VIIa/TF complex
Proteins C/S blocks VIIIa and VA
Anti-thrombin blocks IX,X,XI,XII
Plasminogen activator activates pllasmin to degrade fibrin

Question 3

three regulators of fibrinolysis

Answer 3

TAFI, PAI, a;pha2-antiplasmin

Question 4

4 classes of platelet disorders

Answer 4

aggregation
adhesion
secretion (uremia,nsaids)
‘activity’ (scott’s syndrome)

Question 5

Two predictors of menorrhagia

Answer 5

> 1inch clots

changing fully engorged tampon more than hourly

Question 6

4 common herbs associated with increased bleeding

Answer 6

garlic
ginkgo
ginseng
tumeric
mother wort and redclover have coumarin

Question 7

3 common supplements that impair platelet function

Answer 7

vitamin E, omega-3 and fish oil

Question 8

risk of DVT in octogenarians

Answer 8

1/200

Question 9

Two common/tested often risk factors for throbosis

Answer 9

prothrombin gene mutation

Factor V Leiden

Question 10

4 things that can prolong PT only

Answer 10

VIIa def.
earl Vit. K def.
warfarin AC
Direct Xa

Question 11

3 things that can prolong aPTT and PT

Answer 11

direct thrombin inhibitors
late vitamin K def
II,V,X or fibrinogen def.

Question 12

antiphospholipid Abs are frequently ….

Answer 12

transiently positive in acute illness

Question 13

three major components of the hemostatic system

Answer 13

platelets/formed elements
vessel wall
plasma proteins (clotting factors and fibrinolytic factors