Haemostasis + inherited bleeding disorders Flashcards
Fuel supply in platelets
Alpha granules and DNA bodies
Most abundant glycoprotein molecule receptors on platelets
GpIIb/IIIa heterodimer complex
GpIb
Phospholipid in platelet cell membrane
Associated with prostaglandin synthesis, calcium mobilisation, localisation of coagulant activity to the platelet surface
Alpha granules
VWF
Platelet factor 4
fibrinogen
Tissue plasminogen activator inhibitor-1
Bernard Soulier syndrome
Lack GpIb
Between platelets and VWF
Glanzmann’s syndrome
Lack GpIIb/IIIa
Treatment for BS + G syndrome
Platelets
Novoseven
Von Willebrand disease Type 1
Mild to moderate deficiency of vWF
VWD Type 2
vWF protein present but defective
qualitative + quantitative deficiency
VWD Type 3
Total absent protein
Desmopressin (DDAVP)
Mild cases VWF
Contains tranexamic acid
Tissue factor
Present on subendothelial tissue
Expressed by cells which are normally exposed to flowing blood
Physical injury exposes TF to flowing blood
Tissue factor function
Necessary for initiation of coagulation
Via factor VII
Serum
Plasma without clotting factors
Thrombin time measures
fibrinogen –> fibrin
Factor 7 problem
PT fucked
Factor 8 problem
APTT fucked
Haemophilia A
Factor 8 problem
Haemophilia B
Factor 9 problem
Antithrombin
Major inhibitor of thrombin and Xa
Also inhibits VII, IX and XI
Member of SERine Protease INhibitor family
Antithrombin with heparin
Antithrombin inhibitory activity increases 5-10,000 fold in presence of heparin
Protein C
Activated by thrombin Anti-clotting agent Form of serine protease Inactivates Va and VIIIa Prevents clot from spreading
Protein S
Cofactor for Activated Protein C
