True for von-willebrand disease
High-Yield Explanation
VW factor- On trauma leads to formation of platelet plug at the site- Extrinsic pathway is activated (V, VII) - Intrinsic pathway is activated (VIII, etc) -Fibrin Fibrin insoluble Platelet plug is tested by bleeding time Extrinsic pathway is tested by prothrombin time (PT) Intrinsic pathway is tested by aPTT (activated paial PT) VWF plays a vital pa in the link between platelet plug + intrinsic factor Therefore, VWF if affected due to some reason then BT || & aPTT || but PT Normal IOC for VWD - RISTOCEIN aggregation test