Which plasma protein is necessary for adhesion of platelets to subendothelial fibres?: (A) Glycoprotein IIb, (B) Von Willebrand factor, (C) Platelet factor 3, (D) Factor X
Answer is B. b. Von Willebrand factor(Ref: Nelson's 20/e p 2386-2390, Ghai 8/e p 349)Von Willebrand factor present in plasma and expressed on endothelium after tissue injury is necessary for platelet adhesion with the help of Gp Ib/IX on platelets.