Coagulation Flashcards
How does aspirin work?
Irriversibly inhibits cyclooxygenase thereby inhibiting TXA2 synthesis.
How does clopidogrel work?
Inhibits ADP induced expression of Gp2b/3a.
Function of vWF?
Helps in primary haemostasis, binds to exposed collagen, platelets bind vWF via Gp1b receptor at the site of injury. Platelets undergo conformational change.
CARRIES AND PROTECTS FACTOR 8!
How do you measure the effect of heparin?
PTT
Coagulation factors involved in intrinsic pathway and how is it measured?
12, 11, 9, 8
THE NEXT FACTOR STARTS WITH THE LAST LETTER OF THE PREVIOUS FACTOR!
PTT
More letters than PT so more factors.
Activated by surface activation, sub-endothelial collagen SEC, more letters than TT
Coagulation factors in the extrinsic pathway and how is it measured?
7
PT
Tissue activation, tissue thromboplastin PT, less letters than SEC.
How is warfarin therapy monitored?
Prothrombin time PT, INR
What measures the common pathway?
TT
Starts with activated factor 5
What does PTT measure?
Intrinsic pathway and common pathway.
12, 11, 9, 8, 10, 5, 2 and 1
Heparin therapy
What does PT measure?
Extrinsic pathway and common pathway.
7, 5, 10, 2 and 1
Warfarin therapy (INR)
Features of platelet disorders?
Superficial bleeding into skin, mucosal membranes.
Bleeding immediately after injury.
Features of coagulation disorders?
Bleeding into deep tissues, muscles, joints
Delayed but severe bleeding after injury
Bleeding often prolonged.
Normal platelet count?
150-400x10^9g/l
PT/PTT of platelet disorders?
Normal
Who does acute ITP commonly affect?
Children