Hemostasis and Thrombosis

Question 1

How does blood clot

Answer 1

Primary Hemostasis (platelets activated and form plug with phoshpholipid surface)
Secondary hemostasis (coag factors generate thrombin and fibrin forms on platelets)
Hemostasis stops (regulatory proteins shut off thrombin generation)
Fibrinolysis

Question 2

What is the different between prothombin time and partial thrombin time in what part of the cascade they look at

Answer 2

Prothombin time (PT and INR) look at tissue factor/VIIIa through the final common pathway 
Partial thromboplastin time (aPTT) does not add in tissue factor so only looks at left side of pathway (starting at XIIa) through final common pathway

Question 3

What are three things that stop hemostasis

Answer 3

Protein C, Protein S, and antithrombin

Question 4

What is the difference between primary hemostatic defect and seconday hemostatic defect

Answer 4

Primary: problem with platelets or vascular wall, congenital common, acquired very common
Secondary: problem with clotting factors, congenital uncommon, acquired very rare

Question 5

Bleeding patterns with a platelet problem

Answer 5

Prolonged initial bleeding
Petechiae
Mucosal Bleeding
Bruising

Question 6

Bleeding patterns with a factor problem

Answer 6

Late re-bleeding
Hemarthroses
Ecchymosis
Soft tissue bleeding

Question 7

Iron deficiency summary

Answer 7

lead deficiency - low ferritin test