Major source of Von willebrand factor (vWF) ?

Ans. is 'c' i.e., Endothelial cells o Circulating factor VIII has two components. (a) Factor VIIIc (Procoagulant protein) o This is the smaller component o It is synthesized in liver (main source) and kidney. It is an intrinsic pathway component required for activation of factor X. (b) Von willebrand factor (vWF) o This is the larger component It is produced by endothelial cells (main source) and megakaryocytes. o It has two major functions. (i) Helps in platelet adhesion by interacting platelet membrane glycoprotein lb-IX. (ii) Stabilizes factor VIIIc.