What is the activation order of the intrinsic coagulation pathway?

Get ready for the CAMLPR Hematology Test. Use our quizzes, flashcards, and detailed explanations to enhance your understanding. Prepare confidently for your exam!

Multiple Choice

What is the activation order of the intrinsic coagulation pathway?

Intrinsic coagulation starts with contact activation on a surface, where HMWK acts as a cofactor and prekallikrein becomes kallikrein. This initiates the cascade by converting factor XII to XIIa. From there the path proceeds in a domino fashion: XIIa activates XI to XIa; XIa activates IX to IXa; IXa, with VIIIa as a cofactor, then activates X to Xa. In terms of which components become active, the sequence begins with HMWK and kallikrein, then XII, then XI, then IX, then VIII, and finally X. This arrangement reflects how the intrinsic pathway is set up: the contact activation step precedes the activation of the subsequent factors, and the formation of the IXa–VIIIa tenase complex drives the final activation of X.

Intrinsic coagulation starts with contact activation on a surface, where HMWK acts as a cofactor and prekallikrein becomes kallikrein. This initiates the cascade by converting factor XII to XIIa. From there the path proceeds in a domino fashion: XIIa activates XI to XIa; XIa activates IX to IXa; IXa, with VIIIa as a cofactor, then activates X to Xa. In terms of which components become active, the sequence begins with HMWK and kallikrein, then XII, then XI, then IX, then VIII, and finally X. This arrangement reflects how the intrinsic pathway is set up: the contact activation step precedes the activation of the subsequent factors, and the formation of the IXa–VIIIa tenase complex drives the final activation of X.

More practice questions