22: Hemostasis Flashcards
1
Q
What cell forms thrombocytes?
A
Megakaryocytes
2
Q
What regulates formation of thrombocytes?
A
TPO; thrombopoeitin
3
Q
What two organs produce TPO?
A
Liver and kidneys
4
Q
TPO mechanism
A
Increases hematopoietic SCs -> more megakaryotyctes -> more platelets
5
Q
Receptor for TPO and what cells it’s found on
A
C-MPL; megakaryocytes and other hematopoietic cells
6
Q
High vs low platelet count affect on TPO
A
- High # of platelets -> TPO binds c-MPL receptor -> internalized and degraded -> little free TPO
- Low # of platelets -> little TPO bound to c-MPL receptor -> not degraded -> high levels of TPO remains free
7
Q
What generates thromboxane A2?
A
COX1 and cyco-oxygenase
8
Q
Aspririn mechanism
A
Inhibits cyclo-oxygenate -> reduces thromboxane A2 -> reduces clotting
9
Q
Plavix (Clopidogrel) mechanism
A
Inhibits P2Y12 receptor -> blocks further platelet aggregation via fibrinogen
10
Q
Protein C role in anti-coagulation
A
Inactivates tPA’s inhibitor
