Biochemistry of Coagulation Flashcards
What are the three types of granules a platelet contains?
- Electron dense granules
- Alpha-granule
- Lysosomal granules
What are the four phases of hemostasis?
- Vascular constriction
- Activate Platelets, form platelet plug
- Form fibrin mesh, trap platelet plug
- Dissolve clot
What is contained within the electron rich granule?
ADP, ATP, calcium, serotonin
What is contained within the alpha granule?
Heparin antagonist Platelet derived growth factor B-thromboglobulin Fibrinogen Von Willebrand's factor
What is it that is bound and stabilized by vW factor??
Factor VIII
What is the underlying deficiency in hemophilia A?
Factor VIII
There are three types of vW disease. What differentiates them?
1: Not enough being made
2: Deficiency in vW factor
3: Nothing being made
What is the disorder that is diagnosed by presence of schistocytes/microangiopathic hemolytic anemia and thrombocytopenia?
Thrombotic thrombocytic purpura
What is the deficiency in thrombotic thrombocytic purpura?
ADAMTS13
What is it the intracellular mechanism that causes a platelet to convert to spherical shape?
Calcium storage release and myosin/light chain interactions
What initiates the calcium influx for platelets to change shape?
ADP binding to surface
The internal calcium release causes important cytokines to be released. What are they?
Arachidonic acid, leading to an increase of Thromboxane A2
What is the role of thromboxane A2?
Vasoconstrictor, causes further platelet aggregation
GPIIb-GPIIIa is a receptor for what two molecules?
vWF and fibrinogen
Abciximab inhibits what?
GPIIb-GP-IIIa
