During a laboratory exercise on coagulation testing, a 23-year-old medical student is found to have a prolonged bleeding time. She has had a long history of "easy bleeding," with frequent bleeding of the gums, epistaxis, cutaneous bleeding, and menorrhagia. Fuher testing revealed a deficiency of Von Willebrand factor. Which of the following thrombogenic processes involving platelets is most directly impaired?
Disruption of the endothelium exposes subendothelial von Willebrand factor (vWF) and collagen, which promote platelet adherence and activation. Deficiency of Von willebrand factor (VWF) causes | platelet adhesion ( |BT) and | Intrinsic pathway activity ( | aPTT) .
Adhesion
Conformational change with activation of phospholipid surface
Formation of fibrinogen bridges
Release reaction
Hematology