Which of the following clotting factor is not involved in intrinsic pathway?
Intrinsic pathway requires clotting factors VIII, IX, X, XI XII. Factor VII is involved in extrinsic pathway. Other requirements for intrinsic pathway includes proteins such as prekallikrein and high molecular weight kininogen as well as calcium ions and phospholipids secreted from platelets. This pathway is initiated when prekallikrein, high molecular weight kininogen, factor XI and XII are exposed to negatively charged surface. This is called contact phase. Exposure of collagen to a vessel surface is the primary stimulus for the contact phase. Ref: Medical Biochemistry By Sheriff, Page 405; Textbook of Medical Physiology By Guyton and Hall, 10th Edition, Page 423
Factor XII
Factor XI
Factor IX
Factor VII