general homeostasis Flashcards
What are the three natural clotting cascade inhibitors we have talked about?
1) TFPI
2) AT III
3) Proteins S and C
How does blood vessel constriction aid clotting?
1) decrease blood loss
2) bring platelets and clotting factors into contact
What are the two natural clot lysis agents we have talked about?
1) tPA
2) plasmin
What are the two types of granules in platelets and what do they contain?
alpha- fibrinogen and vWf
beta- serotonin, ADP, Ca 2+
What factors are involved in the (S)intrinsic pathway?
12, 11, 9, 8, 5
What factors are involved in the (S)extrinsic pathway?
TF, 7
What factors are involved in the common clotting pathway?
10, thrombin, fibrin
What steps of the (S)intrinsic pathway does protein C inhibit?
factors 5 and 8
TFPI inhibits tissue factor in which clotting pathway?
the (S)extrinsic pathway
What clotting inhibitor inhibits factors 11, 9, TF/ 7 complex, 10, and thrombin?
AT III
What is the only example of negative feedback in the clotting cascade?
activated factor 10 inhibits formation of the TF/ 7 complex
tPA promotes what?
conversion of plasminogen to plasmin
The agent which breaks up clots into Fibrin Degradation Products (FDPs) is what?
plasmin
Tissue factor (TF) is released from/present in what locations?
1) “hidden cells” of the sub-endothelium when they are revealed by damage
2) microparticles are always present in the blood
3) endothelial cells and monocytes during inflammation
What role do phospholipids in platelet membranes play in clotting?
activate coagulation factors
What does glycoprotein (GP) Ia do?
Ia binds collagen
Which glycoprotein (GP) binds vWf?
GP Ib
What does glycoprotein (GP) IIb/IIIa do?
binds fibrinogen
steps for platelet aggregation:
1) proteins exposed
2) platelets adhere
3) granules release
4) platelets aggregate
5) phospholipids exposed
steps for fibrin clot formation:
1) TF exposed
2) cascade begins
3) cascade makes fibrin
4) fibrin solidifies plug
What does a template bleeding time measure and what would an abnormal result indicate?
evaluates platelet response to injury;
a long bleeding time after incision would indicate a platelet disorder
Which platelet test would you use to calculate an “in vitro bleeding time?”
closure time with a platelet function analyzer
You would use a platelet function analyzer that measures how fast platelets occlude holes in a membrane to look for what types of platelet disorders?
aspirin related or von Willebrand factor deficiency platelet disorders
In a platelet aggregation test where aggregating agents are added singly to the patient sample what are you measuring?
a decrease in sample turbidity would indicate aggregation and thus a deficiency of that added factor in the patient sample
